Automated, tiered data retention

ABSTRACT

The automatic, tiered retention storage system according to certain aspects can automatically classify data items based on content, such as based on the inclusion of search terms in the data items, or based on metadata or other characteristics associated with the data. Based on the classification, the system can assign the data items to corresponding user-defined “buckets.” In some embodiments, each bucket is associated with a particular tier in the storage system having a specific retention period.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of priority under 35 U.S.C. §119(e)of U.S. Provisional Patent Application No. 61/608,531, filed on Mar. 8,2012, entitled “AUTOMATED RETENTION POLICY IN A DATA STORAGE SYSTEM,”which is incorporated herein by reference in its entirety.

BACKGROUND

Businesses worldwide recognize the commercial value of their data andseek reliable, cost-effective ways to protect the information stored ontheir computer networks while minimizing impact on productivity.Protecting information is often part of a routine process that isperformed within an organization.

A company might back up critical computing systems such as databases,file servers, web servers, and so on as part of a daily, weekly, ormonthly maintenance schedule. The company may similarly protectcomputing systems used by each of its employees, such as those used byan accounting department, marketing department, engineering department,and so forth.

Given the rapidly expanding volume of data under management, companiesalso continue to seek innovative techniques for managing data growth, inaddition to protecting data. For instance, companies often implementmigration techniques for moving data to lower cost storage over time anddata reduction techniques for reducing redundant data, pruning lowerpriority data, etc.

Enterprises also increasingly view their stored data as a valuableasset. Along these lines, customers are looking for solutions that notonly protect and manage, but also leverage their data. For instance,solutions providing data analysis capabilities, improved datapresentation and access features, and the like, are in increasingdemand.

SUMMARY

Enterprises are generating ever increasing volumes of data andcorresponding storage requirements. However, different types of data mayhave varying degrees of importance, and all of the data may not need tobe retained according to the same criteria, such as for the same periodof time.

Due to the above challenges, there is a need for a data storage systemthat implements a data retention policy in an efficient manner. In orderto address these and other challenges, certain storage systems disclosedherein automatically classify stored data (e.g., backup and/or primary,production data) into a set of pre-defined groups according to aretention scheme. The system can also automatically prune the data basedon various retention periods associated with the pre-defined groups.Depending on the configuration, the system classifies the data based onthe contents, type, or other characteristics (e.g., metadata) associatedwith the data.

The automatic, tiered retention storage system according to certainaspects can automatically classify data items based on content,metadata, or any other appropriate characteristic of the data, andassign the data items to corresponding user-defined “buckets.” In someembodiments, each bucket is associated with a particular tier in thestorage system having a specific retention period. The criteria forclassification can be defined according to user-preference. For example,the user may wish to classify files based on content using search termsand/or based on metadata. Files can be classified based on subjectmatter (e.g., as indicated by content and/or metadata), for example,some other appropriate parameter associated with the files, or anycombination thereof. Emails, for instance, may be classified accordingto subject line content, sender, recipient, message body content,presence, or type of attachment(s), etc. The automatic classificationmay be implemented as part of a broader storage policy.

A user-defined retention policy can specify the retention periodsassociated with the buckets, or the retention periods can beautomatically assigned, e.g., to a default retention period. After thedata is classified according to the criteria in the policy and assignedto the appropriate bucket, it can be copied or otherwise associated withthe appropriate bucket (e.g., migrated to an appropriate tier). The datain a particular bucket is kept in the bucket for the specified retentionperiod, and pruned when the retention period is met.

In this manner, the automated, tiered retention data storage system canfacilitate management and reduction of data by making classification ofdata items and their retention in various buckets automatic. The systemworks as a filter, and allows for efficient migration and/or pruning ofdata in a meaningful, intelligent manner, according to the needs of theorganization. Rather than having to manually extract the data items toretain for a certain period of time, the user can define a retentionpolicy to store the designated items (e.g., all emails associated with aCEO or other employee) for a specified length of time, and theautomatic, tiered retention storage system automates the process. Inthis way, the user or system administrator can save a significant amountof time and effort in managing and reducing the amount of data in anorganization.

According to certain embodiments, a method is provided for automatic,tiered data retention in a networked data storage system. The method caninclude copying primary data comprising a plurality of data itemsgenerated by one or more applications executing on one or more clientcomputers from primary storage to secondary storage. The method mayfurther include accessing a user-defined data retention policycomprising a set of criteria for assigning the data items to a pluralityof retention containers within the secondary storage, each retentioncontainer associated with a particular retention period, theclassification criteria for at least a first of the retention containerscomprising at least one search term. The method can additionally includeusing one or more computer processors, parsing through the data items todetermine which data items contain an instance of the search termassociated with the first retention container. For one or more firstdata items that contain an instance of the search term associated withthe first retention container, the method can include: assigning thefirst data items to the first retention container at least in part basedon the determination that the first data items contain the search term;and pruning the first data items from the first retention container onlyafter the first data items have been retained for a duration that is atleast as long as the retention period associated with the firstretention container.

In some embodiments, a data storage system is provided for automatic,tiered data retention. The system may include a storage manager moduleexecuting in one or more processors and configured to initiate copyingof primary data comprising a plurality of data items generated by one ormore applications executing on one or more client computers from primarystorage to secondary storage. The system may also include a tieredretention module executing in one or more processors. The tieredretention module can be configured to access a user-defined dataretention policy comprising a set of criteria for assigning the dataitems to a plurality of retention containers within the secondarystorage, each retention container associated with a particular retentionperiod, the classification criteria for at least a first of theretention containers comprising at least one search term. The tieredretention module may be further configured to parse through the dataitems to determine which data items contain an instance of the searchterm associated with the first retention container. The tiered retentionmodule can be further configured to: for one or more first data itemsthat contain an instance of the search term associated with the firstretention container: assign the one or more first data items to thefirst retention container at least in part based on the determinationthat the one or more first data items contain the search term; detectthat the one or more first data items have been retained for a period oftime corresponding to the retention period, or at least a period of timecorresponding to the retention period, associated with the firstretention container; and in response to said detecting, prune the one ormore first data items from the first retention container.

According to other aspects of the disclosure, a method is provided forautomatic, tiered data retention in a data storage system. The methodcan include accessing a data retention policy comprising a set ofcriteria for assigning a plurality of data items stored in a firststorage device to a plurality of retention containers, each retentioncontainer associated with a particular retention period, the data itemsgenerated by at least one user application operating on a firstcomputing device. The method may further include using one or morecomputer processors, parsing through the data items to determine whichdata items meet the classification criteria. For one or more first dataitems of the plurality of data items that meet the classificationcriteria associated with a first retention container of the plurality ofretention containers, the method can include: assigning the one or morefirst data items to the first retention container at least in part basedon the determination that the first data items meet the classificationcriteria; and pruning the one or more first data items from the firstretention container after the first data items have been retained for aduration that is at least as long as the retention period associatedwith the first retention container. For one or more second data items ofthe plurality of data items that meet the classification criteriaassociated with a second retention container of the plurality ofretention containers, the method includes assigning the one or moresecond data items to the second retention container at least in partbased on the determination that the second data items meet theclassification criteria, and pruning the one or more second data itemsfrom the second retention container after the second data items havebeen retained for a duration that is at least as long as the retentionperiod associated with the second retention container.

According to yet further aspects of the disclosure, a method is providedfor automatic, tiered data retention in a networked data storage system.The method can include copying primary data comprising a plurality offiles generated by one or more client computers from primary storage tosecondary storage. The method may further include accessing a dataretention policy including classification criteria associated with eachof a plurality of buckets in the secondary storage having correspondingretention periods associated therewith, wherein individual files in theplurality of files belong to a particular bucket of the plurality ofbuckets if the individual files meet the classification criteriaassociated with the particular bucket. The method can additionallyinclude using one or more computer processors, automatically processing,based on the data retention policy, a first file of the plurality offiles to determine that the first file belongs to a first bucket of theplurality of buckets that is associated with a first retention period.The method can further include using one or more computer processors,automatically processing, based on the data retention policy, the firstfile of the plurality of files to determine that the first file alsobelongs to a second bucket of the plurality of buckets that isassociated with a second retention period that is longer than the firstretention period. The method may additionally include associating afirst instance of the first file with the first bucket, and associatinga second instance of the first file with the second bucket.

According to other embodiments, a data storage system is provided forautomatic, tiered data retention. The system can include a storagemanager module executing in one or more processors and configured toinitiate copying of primary data comprising a plurality of data itemsgenerated by one or more applications executing on one or more clientcomputers from primary storage to secondary storage. The system mayfurther include a tiered retention module executing in one or moreprocessors. The tiered retention module can be configured to access adata retention policy comprising a set of classification rules forclassifying the files into a plurality of buckets within the secondarystorage, each bucket associated with a particular retention period. Thetiered retention module may be further configured to, using one or morecomputer processors, automatically process, based on the retentionpolicy, a first file of the plurality of files to determine that thefirst file belongs to a first bucket of the plurality of bucketsassociated with a first retention period. The tiered retention modulecan be further configured to, using one or more computer processors,automatically process, based on the retention policy, the first file ofthe plurality of files to determine that the first file belongs to asecond bucket of the plurality of buckets associated with a secondretention period that is longer than the first retention period. Thetiered retention module may additionally be configured to associate afirst instance of the first file with the first bucket, and associate asecond instance of the first file with the second bucket.

For purposes of summarizing the disclosure, certain aspects, advantagesand novel features of the inventions have been described herein. It isto be understood that not necessarily all such advantages may beachieved in accordance with any particular embodiment of the invention.Thus, the invention may be embodied or carried out in a manner thatachieves or optimizes one advantage or group of advantages as taughtherein without necessarily achieving other advantages as may be taughtor suggested herein.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a block diagram illustrating an exemplary informationmanagement system.

FIG. 1B is a detailed view of a primary storage device, a secondarystorage device, and some examples of primary data and secondary copydata.

FIG. 1C is a block diagram of an exemplary information management systemincluding a storage manager, one or more data agents, and one or moremedia agents.

FIG. 1D is a block diagram illustrating a scalable informationmanagement system.

FIG. 1E illustrates certain secondary copy operations according to anexemplary storage policy.

FIG. 2 is a block diagram of an exemplary storage system configured toimplement automatic, tiered retention of user data according to certainembodiments.

FIG. 3A is a data flow diagram illustrative of the interaction betweenthe various components of an exemplary storage system configured toimplement automatic, tiered retention according to certain embodiments.

FIG. 3B is a data flow diagram illustrative of the interaction betweenthe various components of another exemplary storage system configured toimplement automatic, tiered retention according to certain embodiments.

FIG. 4 is a flow diagram illustrative of one embodiment of a routine forautomatically classifying data and copying the data to various buckets.

FIG. 5 is a schematic diagram illustrating an exemplary logical view ofa hierarchy of buckets within a storage system that implementsautomatic, tiered retention, according to some embodiments.

DETAILED DESCRIPTION

Systems and methods are described herein for implementing automatedretention policy in a data storage system. Examples of such systems andmethods are discussed in further detail herein, e.g., with respect toFIGS. 2-5. Automated retention policy may be implemented by informationmanagement systems such as those that will now be described with respectto FIGS. 1A-1E. And, as will be described, the componentry forimplementing automated retention policy described herein can beincorporated into such systems.

Information Management System Overview

With the increasing importance of protecting and leveraging data,organizations simply cannot afford to take the risk of losing criticaldata. Moreover, runaway data growth and other modern realities makeprotecting and managing data an increasingly difficult task. There istherefore a need for efficient, powerful, and user-friendly solutionsfor protecting and managing data.

Depending on the size of the organization, there are typically many dataproduction sources which are under the purview of tens, hundreds, oreven thousands of employees or other individuals. In the past,individual employees were sometimes responsible for managing andprotecting their data. A patchwork of hardware and software pointsolutions have been applied in other cases. These solutions were oftenprovided by different vendors and had limited or no interoperability.

Certain embodiments described herein provide systems and methods capableof addressing these and other shortcomings of prior approaches byimplementing unified, organization-wide information management. FIG. 1Ashows one such information management system 100, which generallyincludes combinations of hardware and software configured to protect andmanage data and metadata generated and used by the various computingdevices in the information management system 100.

The organization which employs the information management system 100 maybe a corporation or other business entity, non-profit organization,educational institution, household, governmental agency, or the like.

Generally, the systems and associated components described herein may becompatible with and/or provide some or all of the functionality of thesystems and corresponding components described in one or more of thefollowing U.S. patents and patent application publications assigned toCommVault Systems, Inc., each of which is hereby incorporated in itsentirety by reference herein:

-   -   U.S. Pat. Pub. No. 2010-0332456, entitled “DATA OBJECT STORE AND        SERVER FOR A CLOUD STORAGE ENVIRONMENT, INCLUDING DATA        DEDUPLICATION AND DATA MANAGEMENT ACROSS MULTIPLE CLOUD STORAGE        SITES”;    -   U.S. Pat. No. 7,035,880, entitled “MODULAR BACKUP AND RETRIEVAL        SYSTEM USED IN CONJUNCTION WITH A STORAGE AREA NETWORK”;    -   U.S. Pat. No. 7,343,453, entitled “HIERARCHICAL SYSTEMS AND        METHODS FOR PROVIDING A UNIFIED VIEW OF STORAGE INFORMATION”;

U.S. Pat. No. 7,395,282, entitled “HIERARCHICAL BACKUP AND RETRIEVALSYSTEM”;

-   -   U.S. Pat. No. 7,246,207, entitled “SYSTEM AND METHOD FOR        DYNAMICALLY PERFORMING STORAGE OPERATIONS IN A COMPUTER        NETWORK”;    -   U.S. Pat. No. 7,747,579, entitled “METABASE FOR FACILITATING        DATA CLASSIFICATION”;    -   U.S. Pat. No. 8,229,954, entitled “MANAGING COPIES OF DATA”;    -   U.S. Pat. No. 7,617,262, entitled “SYSTEM AND METHODS FOR        MONITORING APPLICATION DATA IN A DATA REPLICATION SYSTEM”;    -   U.S. Pat. No. 7,529,782, entitled “SYSTEM AND METHODS FOR        PERFORMING A SNAPSHOT AND FOR RESTORING DATA”;    -   U.S. Pat. No. 8,230,195, entitled “SYSTEM AND METHOD FOR        PERFORMING AUXILIARY STORAGE OPERATIONS”;    -   U.S. Pat. No. 8,364,652, entitled “CONTENT-ALIGNED, BLOCK-BASED        DEDUPLICATION”;    -   U.S. Pat. Pub. No. 2006/0224846, entitled “SYSTEM AND METHOD TO        SUPPORT SINGLE INSTANCE STORAGE OPERATIONS”;    -   U.S. Pat. Pub. No. 2009/0329534, entitled “APPLICATION-AWARE AND        REMOTE SINGLE INSTANCE DATA MANAGEMENT”;    -   U.S. Pat. Pub. No. 2012/0150826, entitled “DISTRIBUTED        DEDUPLICATED STORAGE SYSTEM”;    -   U.S. Pat. Pub. No. 2012/0150818, entitled “CLIENT-SIDE        REPOSITORY IN A NETWORKED DEDUPLICATED STORAGE SYSTEM”;    -   U.S. Pat. No. 8,170,995, entitled “METHOD AND SYSTEM FOR OFFLINE        INDEXING OF CONTENT AND CLASSIFYING STORED DATA”; and    -   U.S. Pat. No. 8,156,086, entitled “SYSTEMS AND METHODS FOR        STORED DATA VERIFICATION”.

The illustrated information management system 100 includes one or moreclient computing device 102 having at least one application 110executing thereon, and one or more primary storage devices 104 storingprimary data 112. The client computing device(s) 102 and the primarystorage devices 104 may generally be referred to in some cases as aprimary storage subsystem 117.

Depending on the context, the term “information management system” canrefer to generally all of the illustrated hardware and softwarecomponents. Or, in other instances, the term may refer to only a subsetof the illustrated components.

For instance, in some cases information management system 100 generallyrefers to a combination of specialized components used to protect, move,manage, manipulate and/or process data and metadata generated by theclient computing devices 102. However, the term may generally not referto the underlying components that generate and/or store the primary data112, such as the client computing devices 102 themselves, theapplications 110 and operating system residing on the client computingdevices 102, and the primary storage devices 104.

As an example, “information management system” may sometimes refer onlyto one or more of the following components and corresponding datastructures: storage managers, data agents, and media agents. Thesecomponents will be described in further detail below.

Client Computing Devices

There are typically a variety of sources in an organization that producedata to be protected and managed. As just one illustrative example, in acorporate environment such data sources can be employee workstations andcompany servers such as a mail server, a web server, or the like. In theinformation management system 100, the data generation sources includethe one or more client computing devices 102.

The client computing devices 102 may include, without limitation, one ormore: workstations, personal computers, desktop computers, or othertypes of generally fixed computing systems such as mainframe computersand minicomputers.

The client computing devices 102 can also include mobile or portablecomputing devices, such as one or more laptops, tablet computers,personal data assistants, mobile phones (such as smartphones), and othermobile or portable computing devices such as embedded computers, set topboxes, vehicle-mounted devices, wearable computers, etc.

In some cases, each client computing device 102 is associated with oneor more users and/or corresponding user accounts, of employees or otherindividuals.

The term “client computing device” is used herein because theinformation management system 100 generally “serves” the data managementand protection needs for the data generated by the client computingdevices 102. However, the use of this term does not imply that theclient computing devices 102 cannot be “servers” in other respects. Forinstance, a particular client computing device 102 may act as a serverwith respect to other devices, such as other client computing devices102. As just a few examples, the client computing devices 102 caninclude mail servers, file servers, database servers, and web servers.

The client computing devices 102 may additionally include virtualizedand/or cloud computing resources. For instance, one or more virtualmachines may be provided to the organization by a third-party cloudservice vendor. Or, in some embodiments, the client computing devices102 include one or more virtual machine(s) running on a virtual machinehost computing device operated by the organization. As one example, theorganization may use one virtual machine as a database server andanother virtual machine as a mail server. A virtual machine manager(VMM) (e.g., a Hypervisor) may manage the virtual machines, and resideand execute on the virtual machine host computing device.

Each client computing device 102 may have one or more applications 110(e.g., software applications) executing thereon which generate andmanipulate the data that is to be protected from loss.

The applications 110 generally facilitate the operations of anorganization (or multiple affiliated organizations), and can include,without limitation, mail server applications (e.g., Microsoft ExchangeServer), file server applications, mail client applications (e.g.,Microsoft Exchange Client), database applications (e.g., SQL, Oracle,SAP, Lotus Notes Database), word processing applications (e.g.,Microsoft Word), spreadsheet applications, financial applications,presentation applications, browser applications, mobile applications,entertainment applications, and so on.

The applications 110 can include at least one operating system (e.g.,Microsoft Windows, Mac OS X, iOS, IBM z/OS, Linux, other Unix-basedoperating systems, etc.), which may support one or more file systems andhost the other applications 110.

As shown, the client computing devices 102 and other components in theinformation management system 100 can be connected to one another viaone or more communication pathways 114. The communication pathways 114can include one or more networks or other connection types including asany of following, without limitation: the Internet, a wide area network(WAN), a local area network (LAN), a Storage Area Network (SAN), a FibreChannel connection, a Small Computer System Interface (SCSI) connection,a virtual private network (VPN), a token ring or TCP/IP based network,an intranet network, a point-to-point link, a cellular network, awireless data transmission system, a two-way cable system, aninteractive kiosk network, a satellite network, a broadband network, abaseband network, other appropriate wired, wireless, or partiallywired/wireless computer or telecommunications networks, combinations ofthe same or the like. The communication pathways 114 in some cases mayalso include application programming interfaces (APIs) including, e.g.,cloud service provider APIs, virtual machine management APIs, and hostedservice provider APIs.

Primary Data and Exemplary Primary Storage Devices

Primary data 112 according to some embodiments is production data orother “live” data generated by the operating system and otherapplications 110 residing on a client computing device 102. The primarydata 112 is stored on the primary storage device(s) 104 and is organizedvia a file system supported by the client computing device 102. Forinstance, the client computing device(s) 102 and correspondingapplications 110 may create, access, modify, write, delete, andotherwise use primary data 112.

Primary data 112 is generally in the native format of the sourceapplication 110. According to certain aspects, primary data 112 is aninitial or first (e.g., created before any other copies or before atleast one other copy) stored copy of data generated by the sourceapplication 110. Primary data 112 in some cases is created substantiallydirectly from data generated by the corresponding source applications110.

The primary data 112 may sometimes be referred to as a “primary copy” inthe sense that it is a discrete set of data. However, the use of thisterm does not necessarily imply that the “primary copy” is a copy in thesense that it was copied or otherwise derived from another storedversion.

The primary storage devices 104 storing the primary data 112 may berelatively fast and/or expensive (e.g., a disk drive, a hard-disk array,solid state memory, etc.). In addition, primary data 112 may be intendedfor relatively short term retention (e.g., several hours, days, orweeks).

According to some embodiments, the client computing device 102 canaccess primary data 112 from the primary storage device 104 by makingconventional file system calls via the operating system. Primary data112 representing files may include structured data (e.g., databasefiles), unstructured data (e.g., documents), and/or semi-structureddata. Some specific examples are described below with respect to FIG.1B.

It can be useful in performing certain tasks to break the primary data112 up into units of different granularities. In general, primary data112 can include files, directories, file system volumes, data blocks,extents, or any other types or granularities of data objects. As usedherein, a “data object” can refer to both (1) any file that is currentlyaddressable by a file system or that was previously addressable by thefile system (e.g., an archive file) and (2) a subset of such a file.

As will be described in further detail, it can also be useful inperforming certain functions of the information management system 100 toaccess and modify metadata within the primary data 112. Metadatagenerally includes information about data objects or characteristicsassociated with the data objects.

Metadata can include, without limitation, one or more of the following:the data owner (e.g., the client or user that generates the data), thelast modified time (e.g., the time of the most recent modification ofthe data object), a data object name (e.g., a file name), a data objectsize (e.g., a number of bytes of data), information about the content(e.g., an indication as to the existence of a particular search term),to/from information for email (e.g., an email sender, recipient, etc.),creation date, file type (e.g., format or application type), lastaccessed time, application type (e.g., type of application thatgenerated the data object), location/network (e.g., a current, past orfuture location of the data object and network pathways to/from the dataobject), frequency of change (e.g., a period in which the data object ismodified), business unit (e.g., a group or department that generates,manages or is otherwise associated with the data object), and aginginformation (e.g., a schedule, such as a time period, in which the dataobject is migrated to secondary or long term storage), boot sectors,partition layouts, file location within a file folder directorystructure, user permissions, owners, groups, access control lists[ACLs]), system metadata (e.g., registry information), combinations ofthe same or the like.

In addition to metadata generated by or related to file systems andoperating systems, some of the applications 110 maintain indices ofmetadata for data objects, e.g., metadata associated with individualemail messages. Thus, each data object may be associated withcorresponding metadata. The use of metadata to perform classificationand other functions is described in greater detail below.

Each of the client computing devices 102 are associated with and/or incommunication with one or more of the primary storage devices 104storing corresponding primary data 112. A client computing device 102may be considered to be “associated with” or “in communication with” aprimary storage device 104 if it is capable of one or more of: storingdata to the primary storage device 104, retrieving data from the primarystorage device 104, and modifying data retrieved from a primary storagedevice 104.

The primary storage devices 104 can include, without limitation, diskdrives, hard-disk arrays, semiconductor memory (e.g., solid statedrives), and network attached storage (NAS) devices. In some cases, theprimary storage devices 104 form part of a distributed file system. Theprimary storage devices 104 may have relatively fast I/O times and/orare relatively expensive in comparison to the secondary storage devices108. For example, the information management system 100 may generallyregularly access data and metadata stored on primary storage devices104, whereas data and metadata stored on the secondary storage devices108 is accessed relatively less frequently.

In some cases, each primary storage device 104 is dedicated to anassociated client computing devices 102. For instance, a primary storagedevice 104 in one embodiment is a local disk drive of a correspondingclient computing device 102. In other cases, one or more primary storagedevices 104 can be shared by multiple client computing devices 102. Asone example, a primary storage device 104 can be a disk array shared bya group of client computing devices 102, such as one of the followingtypes of disk arrays: EMC Clariion, EMC Symmetrix, EMC Celerra, DellEqualLogic, IBM XIV, NetApp FAS, HP EVA, and HP 3PAR.

The information management system 100 may also include hosted services(not shown), which may be hosted in some cases by an entity other thanthe organization that employs the other components of the informationmanagement system 100. For instance, the hosted services may be providedby various online service providers to the organization. Such serviceproviders can provide services including social networking services,hosted email services, or hosted productivity applications or otherhosted applications).

Hosted services may include software-as-a-service (SaaS),platform-as-a-service (PaaS), application service providers (ASPs),cloud services, or other mechanisms for delivering functionality via anetwork. As it provides services to users, each hosted service maygenerate additional data and metadata under management of theinformation management system 100, e.g., as primary data 112. In somecases, the hosted services may be accessed using one of the applications110. As an example, a hosted mail service may be accessed via browserrunning on a client computing device 102.

Secondary Copies and Exemplary Secondary Storage Devices

The primary data 112 stored on the primary storage devices 104 may becompromised in some cases, such as when an employee deliberately oraccidentally deletes or overwrites primary data 112 during their normalcourse of work. Or the primary storage devices 104 can be damaged orotherwise corrupted.

For recovery and/or regulatory compliance purposes, it is thereforeuseful to generate copies of the primary data 112. Accordingly, theinformation management system 100 includes one or more secondary storagecomputing devices 106 and one or more secondary storage devices 108configured to create and store one or more secondary copies 116 of theprimary data 112 and associated metadata. The secondary storagecomputing devices 106 and the secondary storage devices 108 may bereferred to in some cases as a secondary storage subsystem 118.

Creation of secondary copies 116 can help meet information managementgoals, such as: restoring data and/or metadata if an original version(e.g., of primary data 112) is lost (e.g., by deletion, corruption, ordisaster); allowing point-in-time recovery; complying with regulatorydata retention and electronic discovery (e-discovery) requirements;reducing utilized storage capacity; facilitating organization and searchof data; improving user access to data files across multiple computingdevices and/or hosted services; and implementing data retentionpolicies.

Types of secondary copy operations can include, without limitation,backup operations, archive operations, snapshot operations, replicationoperations (e.g., continuous data replication [CDR]), data retentionpolicies such as or information lifecycle management and hierarchicalstorage management operations, and the like. These specific typesoperations are discussed in greater detail below.

Regardless of the type of secondary copy operation, the client computingdevices 102 access or receive primary data 112 and communicate the data,e.g., over the communication pathways 114, for storage in the secondarystorage device(s) 108.

A secondary copy 116 can comprise a separate stored copy of applicationdata that is derived from one or more earlier created, stored copies(e.g., derived from primary data 112 or another secondary copy 116).Secondary copies 116 can include point-in-time data, and may be intendedfor relatively long-term retention (e.g., weeks, months or years),before some or all of the data is moved to other storage or isdiscarded.

In some cases, a secondary copy 116 is a copy of application datacreated and stored subsequent to at least one other stored instance(e.g., subsequent to corresponding primary data 112 or to anothersecondary copy 116), in a different storage device than at least oneprevious stored copy, and/or remotely from at least one previous storedcopy. Secondary copies 116 may be stored in relatively slow and/or lowcost storage (e.g., magnetic tape). A secondary copy 116 may be storedin a backup or archive format, or in some other format different thanthe native source application format or other primary data format.

In some cases, secondary copies 116 are indexed so users can browse andrestore at another point in time. After creation of a secondary copy 116representative of certain primary data 112, a pointer or other locationindicia (e.g., a stub) may be placed in primary data 112, or beotherwise associated with primary data 112 to indicate the currentlocation on the secondary storage device(s) 108.

Since an instance a data object or metadata in primary data 112 maychange over time as it is modified by an application 110 (or hostedservice or the operating system), the information management system 100may create and manage multiple secondary copies 116 of a particular dataobject or metadata, each representing the state of the data object inprimary data 112 at a particular point in time. Moreover, since aninstance of a data object in primary data 112 may eventually be deletedfrom the primary storage device 104 and the file system, the informationmanagement system 100 may continue to manage point-in-timerepresentations of that data object, even though the instance in primarydata 112 no longer exists.

For virtualized computing devices the operating system and otherapplications 110 of the client computing device(s) 102 may executewithin or under the management of virtualization software (e.g., a VMM),and the primary storage device(s) 104 may comprise a virtual diskcreated on a physical storage device. The information management system100 may create secondary copies 116 of the files or other data objectsin a virtual disk file and/or secondary copies 116 of the entire virtualdisk file itself (e.g., of an entire .vmdk file).

Secondary copies 116 may be distinguished from corresponding primarydata 112 in a variety of ways, some of which will now be described.First, as discussed, secondary copies 116 can be stored in a differentformat (e.g., backup, archive, or other non-native format) than primarydata 112. For this or other reasons, secondary copies 116 may not bedirectly useable by the applications 110 of the client computing device102, e.g., via standard system calls or otherwise without modification,processing, or other intervention by the information management system100.

Secondary copies 116 are also often stored on a secondary storage device108 that is inaccessible to the applications 110 running on the clientcomputing devices 102 (and/or hosted services). Some secondary copies116 may be “offline copies,” in that they are not readily available(e.g. not mounted to tape or disk). Offline copies can include copies ofdata that the information management system 100 can access without humanintervention (e.g. tapes within an automated tape library, but not yetmounted in a drive), and copies that the information management system100 can access only with at least some human intervention (e.g. tapeslocated at an offsite storage site).

The secondary storage devices 108 can include any suitable type ofstorage device such as, without limitation, one or more tape libraries,disk drives or other magnetic, non-tape storage devices, optical mediastorage devices, solid state storage devices, NAS devices, combinationsof the same, and the like. In some cases, the secondary storage devices108 are provided in a cloud (e.g. a private cloud or one operated by athird-party vendor).

The secondary storage device(s) 108 in some cases comprises a disk arrayor a portion thereof. In some cases, a single storage device (e.g., adisk array) is used for storing both primary data 112 and at least somesecondary copies 116. In one example, a disk array capable of performinghardware snapshots stores primary data 112 and creates and storeshardware snapshots of the primary data 112 as secondary copies 116.

The Use of Intermediary Devices For Creating Secondary Copies

Creating secondary copies can be a challenging task. For instance, therecan be hundreds or thousands of client computing devices 102 continuallygenerating large volumes of primary data 112 to be protected. Also,there can be significant overhead involved in the creation of secondarycopies 116. Moreover, secondary storage devices 108 may be specialpurpose components, and interacting with them can require specializedintelligence.

In some cases, the client computing devices 102 interact directly withthe secondary storage device 108 to create the secondary copies 116.However, in view of the factors described above, this approach cannegatively impact the ability of the client computing devices 102 toserve the applications 110 and produce primary data 112. Further, theclient computing devices 102 may not be optimized for interaction withthe secondary storage devices 108.

Thus, in some embodiments, the information management system 100includes one or more software and/or hardware components which generallyact as intermediaries between the client computing devices 102 and thesecondary storage devices 108. In addition to off-loading certainresponsibilities from the client computing devices 102, theseintermediary components can provide other benefits. For instance, asdiscussed further below with respect to FIG. 1D, distributing some ofthe work involved in creating secondary copies 116 can enhancescalability.

The intermediary components can include one or more secondary storagecomputing devices 106 as shown in FIG. 1A and/or one or more mediaagents, which can be software modules residing on correspondingsecondary storage computing devices 106 (or other appropriate devices).Media agents are discussed below (e.g., with respect to FIGS. 1C-1E).

The secondary storage computing device(s) 106 can comprise anyappropriate type of computing device and can include, withoutlimitation, any of the types of fixed and portable computing devicesdescribed above with respect to the client computing devices 102. Insome cases, the secondary storage computing device(s) 106 includespecialized hardware and/or software componentry for interacting withthe secondary storage devices 108.

To create a secondary copy 116, the client computing device 102communicates the primary data 112 to be copied (or a processed versionthereof) to the designated secondary storage computing device 106, viathe communication pathway 114. The secondary storage computing device106 in turn conveys the received data (or a processed version thereof)to the secondary storage device 108. In some such configurations, thecommunication pathway 114 between the client computing device 102 andthe secondary storage computing device 106 comprises a portion of a LAN,WAN or SAN. In other cases, at least some client computing devices 102communicate directly with the secondary storage devices 108 (e.g., viaFibre Channel or SCSI connections).

Exemplary Primary Data and an Exemplary Secondary Copy

FIG. 1B is a detailed view showing some specific examples of primarydata stored on the primary storage device(s) 104 and secondary copy datastored on the secondary storage device(s) 108, with other components inthe system removed for the purposes of illustration. Stored on theprimary storage device(s) 104 are primary data objects including wordprocessing documents 119A-B, spreadsheets 120, presentation documents122, video files 124, image files 126, email mailboxes 128 (andcorresponding email messages 129A-C), html/xml or other types of markuplanguage files 130, databases 132 and corresponding tables 133A-133C).

Some or all primary data objects are associated with a primary copy ofobject metadata (e.g., “Meta1-11”), which may be file system metadataand/or application specific metadata. Stored on the secondary storagedevice(s) 108 are secondary copy objects 134A-C which may include copiesof or otherwise represent corresponding primary data objects andmetadata.

As shown, the secondary copy objects 134A-C can individually representmore than one primary data object. For example, secondary copy dataobject 134A represents three separate primary data objects 133C, 122 and129C (represented as 133C′, 122′ and 129C′, respectively). Moreover, asindicated by the prime mark (′), a secondary copy object may store arepresentation of a primary data object or metadata differently than theoriginal format, e.g., in a compressed, encrypted, deduplicated, orother modified format.

Exemplary Information Management System Architecture

The information management system 100 can incorporate a variety ofdifferent hardware and software components, which can in turn beorganized with respect to one another in many different configurations,depending on the embodiment. There are critical design choices involvedin specifying the functional responsibilities of the components and therole of each component in the information management system 100. Forinstance, as will be discussed, such design choices can impactperformance as well as the adaptability of the information managementsystem 100 to data growth or other changing circumstances.

FIG. 1C shows an information management system 100 designed according tothese considerations and which includes: a central storage orinformation manager 140 configured to perform certain control functions,one or more data agents 142 executing on the client computing device(s)102 configured to process primary data 112, and one or more media agents144 executing on the one or more secondary storage computing devices 106for performing tasks involving the secondary storage devices 108.

Storage Manager

As noted, the number of components in the information management system100 and the amount of data under management can be quite large. Managingthe components and data is therefore a significant task, and a task thatcan grow in an often unpredictable fashion as the quantity of componentsand data scale to meet the needs of the organization.

For these and other reasons, according to certain embodiments,responsibility for controlling the information management system 100, orat least a significant portion of that responsibility, is allocated tothe storage manager 140.

By distributing control functionality in this manner, the storagemanager 140 can be adapted independently according to changingcircumstances. Moreover, a host computing device can be selected to bestsuit the functions of the storage manager 140. These and otheradvantages are described in further detail below with respect to FIG.1D.

The storage manager 140 may be a software module or other application.The storage manager generally initiates, coordinates and/or controlsstorage and other information management operations performed by theinformation management system 100, e.g., to protect and control theprimary data 112 and secondary copies 116 of data and metadata.

As shown by the dashed, arrowed lines, the storage manager 140 maycommunicate with and/or control some or all elements of the informationmanagement system 100, such as the data agents 142 and media agents 144.Thus, in certain embodiments, control information originates from thestorage manager 140, whereas payload data and metadata is generallycommunicated between the data agents 142 and the media agents 144 (orotherwise between the client computing device(s) 102 and the secondarystorage computing device(s) 106), e.g., at the direction of the storagemanager 140. In other embodiments, some information managementoperations are controlled by other components in the informationmanagement system 100 (e.g., the media agent(s) 144 or data agent(s)142), instead of or in combination with the storage manager 140.

According to certain embodiments, the storage manager provides one ormore of the following functions:

-   -   initiating execution of secondary copy operations;    -   managing secondary storage devices 108 and inventory/capacity of        the same;    -   allocating secondary storage devices 108 for secondary storage        operations;    -   monitoring completion of and providing status reporting related        to secondary storage operations;    -   tracking age information relating to secondary copies 116,        secondary storage devices 108, and comparing the age information        against retention guidelines;    -   tracking movement of data within the information management        system 100;    -   tracking logical associations between components in the        information management system 100;    -   protecting metadata associated with the information management        system 100; and    -   implementing operations management functionality.

The storage manager 140 may maintain a database 146 ofmanagement-related data and information management policies 148. Thedatabase 146 may include a management index 150 or other data structurethat stores logical associations between components of the system, userpreferences and/or profiles (e.g., preferences regarding encryption,compression, or deduplication of primary or secondary copy data,preferences regarding the scheduling, type, or other aspects of primaryor secondary copy or other operations, mappings of particularinformation management users or user accounts to certain computingdevices or other components, etc.), management tasks, mediacontainerization, or other useful data. For example, the storage manager140 may use the index 150 to track logical associations between mediaagents 144 and secondary storage devices 108 and/or movement of datafrom primary storage devices 104 to secondary storage devices 108.

Administrators and other employees may be able to manually configure andinitiate certain information management operations on an individualbasis. But while this may be acceptable for some recovery operations orother relatively less frequent tasks, it is often not workable forimplementing on-going organization-wide data protection and management.

Thus, the information management system 100 may utilize informationmanagement policies 148 for specifying and executing informationmanagement operations (e.g., on an automated basis). Generally, aninformation management policy 148 can include a data structure or otherinformation source that specifies a set of parameters (e.g., criteriaand rules) associated with storage or other information managementoperations.

The storage manager database 146 may maintain the information managementpolicies 148 and associated data, although the information managementpolicies 148 can be stored in any appropriate location. For instance, astorage policy may be stored as metadata in a media agent database 152or in a secondary storage device 108 (e.g., as an archive copy) for usein restore operations or other information management operations,depending on the embodiment. Information management policies 148 aredescribed further below.

According to certain embodiments, the storage manager database 146comprises a relational database (e.g., an SQL database) for trackingmetadata, such as metadata associated with secondary copy operations(e.g., what client computing devices 102 and corresponding data wereprotected). This and other metadata may additionally be stored in otherlocations, such as at the secondary storage computing devices 106 or onthe secondary storage devices 108, allowing data recovery without theuse of the storage manager 140.

As shown, the storage manager 140 may include a jobs agent 156, a userinterface 158, and a management agent 154, all of which may beimplemented as interconnected software modules or application programs.

The jobs agent 156 in some embodiments initiates, controls, and/ormonitors the status of some or all storage or other informationmanagement operations previously performed, currently being performed,or scheduled to be performed by the information management system 100.For instance, the jobs agent 156 may access information managementpolicies 148 to determine when and how to initiate and control secondarycopy and other information management operations, as will be discussedfurther.

The user interface 158 may include information processing and displaysoftware, such as a graphical user interface (“GUI”), an applicationprogram interface (“API”), or other interactive interface through whichusers and system processes can retrieve information about the status ofinformation management operations (e.g., storage operations) or issueinstructions to the information management system 100 and itsconstituent components.

The storage manager 140 may also track information that permits it toselect, designate, or otherwise identify content indices, deduplicationdatabases, or similar databases or resources or data sets within itsinformation management cell (or another cell) to be searched in responseto certain queries. Such queries may be entered by the user viainteraction with the user interface 158.

Via the user interface 158, users may optionally issue instructions tothe components in the information management system 100 regardingperformance of storage and recovery operations. For example, a user maymodify a schedule concerning the number of pending secondary copyoperations. As another example, a user may employ the GUI to view thestatus of pending storage operations or to monitor the status of certaincomponents in the information management system 100 (e.g., the amount ofcapacity left in a storage device).

In general, the management agent 154 allows multiple informationmanagement systems 100 to communicate with one another. For example, theinformation management system 100 in some cases may be one informationmanagement subsystem or “cell” of a network of multiple cells adjacentto one another or otherwise logically related in a WAN or LAN. With thisarrangement, the cells may be connected to one another throughrespective management agents 154.

For instance, the management agent 154 can provide the storage manager140 with the ability to communicate with other components within theinformation management system 100 (and/or other cells within a largerinformation management system) via network protocols and applicationprogramming interfaces (“APIs”) including, e.g., HTTP, HTTPS, FTP, REST,virtualization software APIs, cloud service provider APIs, and hostedservice provider APIs. Inter-cell communication and hierarchy isdescribed in greater detail in U.S. Pat. No. 7,035,880, which isincorporated by reference herein.

Data Agents

As discussed, a variety of different types of applications 110 canreside on a given client computing device 102, including operatingsystems, database applications, e-mail applications, and virtualmachines, just to name a few. And, as part of the as part of the processof creating and restoring secondary copies 116, the client computingdevices 102 may be tasked with processing and preparing the primary data112 from these various different applications 110. Moreover, the natureof the processing/preparation can differ across clients and applicationtypes, e.g., due to inherent structural and formatting differencesbetween applications 110.

The one or more data agent(s) 142 are therefore advantageouslyconfigured in some embodiments to assist in the performance ofinformation management operations based on the type of data that isbeing protected, at a client-specific and/or application-specific level.

The data agent 142 may be a software module or component that isgenerally responsible for managing, initiating, or otherwise assistingin the performance of information management operations. For instance,the data agent 142 may take part in performing data storage operationssuch as the copying, archiving, migrating, replicating of primary data112 stored in the primary storage device(s) 104. The data agent 142 mayreceive control information from the storage manager 140, such ascommands to transfer copies of data objects, metadata, and other payloaddata to the media agents 144.

In some embodiments, a data agent 142 may be distributed between theclient computing device 102 and storage manager 140 (and any otherintermediate components) or may be deployed from a remote location orits functions approximated by a remote process that performs some or allof the functions of data agent 142. In addition, a data agent 142 mayperform some functions provided by a media agent 144, e.g., encryptionand deduplication.

As indicated, each data agent 142 may be specialized for a particularapplication 110, and the system can employ multiple data agents 142,each of which may backup, migrate, and recover data associated with adifferent application 110. For instance, different individual dataagents 142 may be designed to handle Microsoft Exchange data, LotusNotes data, Microsoft Windows file system data, Microsoft ActiveDirectory Objects data, SQL Server data, SharePoint data, Oracledatabase data, SAP database data, virtual machines and/or associateddata, and other types of data.

A file system data agent, for example, may handle data files and/orother file system information. If a client computing device 102 has twoor more types of data, one data agent 142 may be used for each data typeto copy, archive, migrate, and restore the client computing device 102data. For example, to backup, migrate, and restore all of the data on aMicrosoft Exchange server, the client computing device 102 may use oneMicrosoft Exchange Mailbox data agent 142 to backup the Exchangemailboxes, one Microsoft Exchange Database data agent 142 to backup theExchange databases, one Microsoft Exchange Public Folder data agent 142to backup the Exchange Public Folders, and one Microsoft Windows FileSystem data agent 142 to backup the file system of the client computingdevice 102. In such embodiments, these data agents 142 may be treated asfour separate data agents 142 by even though they reside on the sameclient computing device 102.

Other embodiments may employ one or more generic data agents 142 thatcan handle and process data from two or more different applications 110,or that can handle and process multiple data types, instead of or inaddition to using specialized data agents 142. For example, one genericdata agent 142 may be used to back up, migrate and restore MicrosoftExchange Mailbox data and Microsoft Exchange Database data while anothergeneric data agent may handle Microsoft Exchange Public Folder data andMicrosoft Windows File System data.

Each data agent 142 may be configured to access data and/or metadatastored in the primary storage device(s) 104 associated with the dataagent 142 and process the data as appropriate. For example, during asecondary copy operation, the data agent 142 may arrange or assemble thedata and metadata into one or more files having a certain format (e.g.,a particular backup or archive format) before transferring the file(s)to a media agent 144 or other component. The file(s) may include a listof files or other metadata. Each data agent 142 can also assist inrestoring data or metadata to primary storage devices 104 from asecondary copy 116. For instance, the data agent 142 may operate inconjunction with the storage manager 140 and one or more of the mediaagents 144 to restore data from secondary storage device(s) 108.

Media Agents

As indicated above with respect to FIG. 1A, off-loading certainresponsibilities from the client computing devices 102 to intermediarycomponents such as the media agent(s) 144 can provide a number ofbenefits including improved client computing device 102 operation,faster secondary copy operation performance, and enhanced scalability.As one specific example which will be discussed below in further detail,the media agent 144 can act as a local cache of copied data and/ormetadata that it has stored to the secondary storage device(s) 108,providing improved restore capabilities.

Generally speaking, a media agent 144 may be implemented as a softwaremodule that manages, coordinates, and facilitates the transmission ofdata, as directed by the storage manager 140, between a client computingdevice 102 and one or more secondary storage devices 108. Whereas thestorage manager 140 controls the operation of the information managementsystem 100, the media agent 144 generally provides a portal to secondarystorage devices 108.

Media agents 144 can comprise logically and/or physically separate nodesin the information management system 100 (e.g., separate from the clientcomputing devices 102, storage manager 140, and/or secondary storagedevices 108). In addition, each media agent 144 may reside on adedicated secondary storage computing device 106 in some cases, while inother embodiments a plurality of media agents 144 reside on the samesecondary storage computing device 106.

A media agent 144 (and corresponding media agent database 152) may beconsidered to be “associated with” a particular secondary storage device108 if that media agent 144 is capable of one or more of: routing and/orstoring data to the particular secondary storage device 108,coordinating the routing and/or storing of data to the particularsecondary storage device 108, retrieving data from the particularsecondary storage device 108, and coordinating the retrieval of datafrom a particular secondary storage device 108.

While media agent(s) 144 are generally associated with one or moresecondary storage devices 108, the media agents 144 in certainembodiments are physically separate from the secondary storage devices108. For instance, the media agents 144 may reside on secondary storagecomputing devices 106 having different housings or packages than thesecondary storage devices 108. In one example, a media agent 144 resideson a first server computer and is in communication with a secondarystorage device(s) 108 residing in a separate, rack-mounted RAID-basedsystem.

In operation, a media agent 144 associated with a particular secondarystorage device 108 may instruct the secondary storage device 108 (e.g.,a tape library) to use a robotic arm or other retrieval means to load oreject a certain storage media, and to subsequently archive, migrate, orretrieve data to or from that media, e.g., for the purpose of restoringthe data to a client computing device 102. The media agent 144 maycommunicate with a secondary storage device 108 via a suitablecommunications link, such as a SCSI or Fiber Channel link.

As shown, each media agent 144 may maintain an associated media agentdatabase 152. The media agent database 152 may be stored in a disk orother storage device (not shown) that is local to the secondary storagecomputing device 106 on which the media agent 144 resides. In othercases, the media agent database 152 is stored remotely from thesecondary storage computing device 106.

The media agent database 152 can include, among other things, an index153 including data generated during secondary copy operations and otherstorage or information management operations. The index 153 provides amedia agent 144 or other component with a fast and efficient mechanismfor locating secondary copies 116 or other data stored in the secondarystorage devices 108. In one configuration, a storage manager index 150or other data structure may store data associating a client computingdevice 102 with a particular media agent 144 and/or secondary storagedevice 108, as specified in a storage policy. A media agent index 153 orother data structure associated with the particular media agent 144 mayin turn include information about the stored data.

For instance, for each secondary copy 116, the index 153 may includemetadata such as a list of the data objects (e.g., files/subdirectories,database objects, mailbox objects, etc.), a path to the secondary copy116 on the corresponding secondary storage device 108, locationinformation indicating where the data objects are stored in thesecondary storage device 108, when the data objects were created ormodified, etc. Thus, the index 153 includes metadata associated with thesecondary copies 116 that is readily available for use in storageoperations and other activities without having to be first retrievedfrom the secondary storage device 108. In yet further embodiments, someor all of the data in the index 153 may instead or additionally bestored along with the data in a secondary storage device 108, e.g., witha copy of the index 153.

Because the index 153 maintained in the database 152 may operate as acache, it can also be referred to as an index cache. In such cases,information stored in the index cache 153 typically comprises data thatreflects certain particulars about storage operations that have occurredrelatively recently. After some triggering event, such as after acertain period of time elapses, or the index cache 153 reaches aparticular size, the index cache 153 may be copied or migrated to asecondary storage device(s) 108. This information may need to beretrieved and uploaded back into the index cache 153 or otherwiserestored to a media agent 144 to facilitate retrieval of data from thesecondary storage device(s) 108. In some embodiments, the cachedinformation may include format or containerization information relatedto archives or other files stored on the storage device(s) 108. In thismanner, the index cache 153 allows for accelerated restores.

In some alternative embodiments the media agent 144 generally acts as acoordinator or facilitator of storage operations between clientcomputing devices 102 and corresponding secondary storage devices 108,but does not actually write the data to the secondary storage device108. For instance, the storage manager 140 (or the media agent 144) mayinstruct a client computing device 102 and secondary storage device 108to communicate with one another directly. In such a case the clientcomputing device 102 transmits the data directly to the secondarystorage device 108 according to the received instructions, and viceversa. In some such cases, the media agent 144 may still receive,process, and/or maintain metadata related to the storage operations.Moreover, in these embodiments, the payload data can flow through themedia agent 144 for the purposes of populating the index cache 153maintained in the media agent database 152, but not for writing to thesecondary storage device 108.

The media agent 144 and/or other components such as the storage manager140 may in some cases incorporate additional functionality, such as dataclassification, content indexing, deduplication, encryption,compression, and the like. Further details regarding these and otherfunctions are described below.

Distributed, Scalable Architecture

As described, certain functions of the information management system 100can be distributed amongst various physical and/or logical components inthe system. For instance, one or more of the storage manager 140, dataagents 142, and media agents 144 may reside on computing devices thatare physically separate from one another. This architecture can providea number of benefits.

For instance, hardware and software design choices for each distributedcomponent can be targeted to suit its particular function. The secondarycomputing devices 106 on which the media agents 144 reside can betailored for interaction with associated secondary storage devices 108and provide fast index cache operation, among other specific tasks.Similarly, the client computing device(s) 102 can be selected toeffectively service the applications 110 residing thereon, in order toefficiently produce and store primary data 112.

Moreover, in some cases, one or more of the individual components in theinformation management system 100 can be distributed to multiple,separate computing devices. As one example, for large file systems wherethe amount of data stored in the storage management database 146 isrelatively large, the management database 146 may be migrated to orotherwise reside on a specialized database server (e.g., an SQL server)separate from a server that implements the other functions of thestorage manager 140. This configuration can provide added protectionbecause the database 146 can be protected with standard databaseutilities (e.g., SQL log shipping or database replication) independentfrom other functions of the storage manager 140. The database 146 can beefficiently replicated to a remote site for use in the event of adisaster or other data loss incident at the primary site. Or thedatabase 146 can be replicated to another computing device within thesame site, such as to a higher performance machine in the event that astorage manager host device can no longer service the needs of a growinginformation management system 100.

The distributed architecture also provides both scalability andefficient component utilization. FIG. 1D shows an embodiment of theinformation management system 100 including a plurality of clientcomputing devices 102 and associated data agents 142 as well as aplurality of secondary storage computing devices 106 and associatedmedia agents 144.

Additional components can be added or subtracted based on the evolvingneeds of the information management system 100. For instance, dependingon where bottlenecks are identified, administrators can add additionalclient computing devices 102, secondary storage devices 106 (andcorresponding media agents 144), and/or secondary storage devices 108.

Moreover, each client computing device 102 in some embodiments cancommunicate with any of the media agents 144, e.g., as directed by thestorage manager 140. And each media agent 144 may be able to communicatewith any of the secondary storage devices 108, e.g., as directed by thestorage manager 140. Thus, operations can be routed to the secondarystorage devices 108 in a dynamic and highly flexible manner. Furtherexamples of scalable systems capable of dynamic storage operations areprovided in U.S. Pat. No. 7,246,207, which is incorporated by referenceherein.

In alternative configurations, certain components are not distributedand may instead reside and execute on the same computing device. Forexample, in some embodiments one or more data agents 142 and the storagemanager 140 reside on the same client computing device 102. In anotherembodiment, one or more data agents 142 and one or more media agents 144reside on a single computing device.

Exemplary Types of Information Management Operations

In order to protect and leverage stored data, the information managementsystem 100 can be configured to perform a variety of informationmanagement operations. As will be described, these operations cangenerally include secondary copy and other data movement operations,processing and data manipulation operations, and management operations.

Data Movement Operations

Data movement operations according to certain embodiments are generallyoperations that involve the copying or migration of data (e.g., payloaddata) between different locations in the information management system100. For example, data movement operations can include operations inwhich stored data is copied, migrated, or otherwise transferred fromprimary storage device(s) 104 to secondary storage device(s) 108, fromsecondary storage device(s) 108 to different secondary storage device(s)108, or from primary storage device(s) 104 to different primary storagedevice(s) 104.

Data movement operations can include by way of example, backupoperations, archive operations, information lifecycle managementoperations such as hierarchical storage management operations,replication operations (e.g., continuous data replication operations),snapshot operations, deduplication operations, single-instancingoperations, auxiliary copy operations, and the like. As will bediscussed, some of these operations involve the copying, migration orother movement of data, without actually creating multiple, distinctcopies. Nonetheless, some or all of these operations are referred to as“copy” operations for simplicity.

Backup Operations

A backup operation creates a copy of primary data 112 at a particularpoint in time. Each subsequent backup copy may be maintainedindependently of the first. Further, a backup copy in some embodimentsis stored in a backup format. This can be in contrast to the version inprimary data 112 from which the backup copy is derived, and which mayinstead be stored in a native format of the source application(s) 110.In various cases, backup copies can be stored in a format in which thedata is compressed, encrypted, deduplicated, and/or otherwise modifiedfrom the original application format. For example, a backup copy may bestored in a backup format that facilitates compression and/or efficientlong-term storage.

Backup copies can have relatively long retention periods as compared toprimary data 112, and may be stored on media with slower retrieval timesthan primary data 112 and certain other types of secondary copies 116.On the other hand, backups may have relatively shorter retention periodsthan some other types of secondary copies 116, such as archive copies(described below). Backups may sometimes be stored at on offsitelocation.

Backup operations can include full, synthetic or incremental backups. Afull backup in some embodiments is generally a complete image of thedata to be protected. However, because full backup copies can consume arelatively large amount of storage, it can be useful to use a fullbackup copy as a baseline and only store changes relative to the fullbackup copy for subsequent backup copies.

For instance, a differential backup operation (or cumulative incrementalbackup operation) tracks and stores changes that have occurred since thelast full backup. Differential backups can grow quickly in size, but canprovide relatively efficient restore times because a restore can becompleted in some cases using only the full backup copy and the latestdifferential copy.

An incremental backup operation generally tracks and stores changessince the most recent backup copy of any type, which can greatly reducestorage utilization. In some cases, however, restore times can berelatively long in comparison to full or differential backups becausecompleting a restore operation may involve accessing a full backup inaddition to multiple incremental backups.

Any of the above types of backup operations can be at the file-level,e.g., where the information management system 100 generally trackschanges to files at the file-level, and includes copies of files in thebackup copy. In other cases, block-level backups are employed, wherefiles are broken into constituent blocks, and changes are tracked at theblock-level. Upon restore, the information management system 100reassembles the blocks into files in a transparent fashion.

Far less data may actually be transferred and copied to the secondarystorage devices 108 during a block-level copy than during a file-levelcopy, resulting in faster execution times. However, when restoring ablock-level copy, the process of locating constituent blocks cansometimes result in longer restore times as compared to file-levelbackups. Similar to backup operations, the other types of secondary copyoperations described herein can also be implemented at either thefile-level or the block-level.

Archive Operations

Because backup operations generally involve maintaining a version of thecopied data in primary data 112 and also maintaining backup copies insecondary storage device(s) 108, they can consume significant storagecapacity. To help reduce storage consumption, an archive operationaccording to certain embodiments creates a secondary copy 116 by bothcopying and removing source data. Or, seen another way, archiveoperations can involve moving some or all of the source data to thearchive destination. Thus, data satisfying criteria for removal (e.g.,data of a threshold age or size) from the source copy may be removedfrom source storage. Archive copies are sometimes stored in an archiveformat or other non-native application format. The source data may beprimary data 112 or a secondary copy 116, depending on the situation. Aswith backup copies, archive copies can be stored in a format in whichthe data is compressed, encrypted, deduplicated, and/or otherwisemodified from the original application format.

In addition, archive copies may be retained for relatively long periodsof time (e.g., years) and, in some cases, are never deleted. Archivecopies are generally retained for longer periods of time than backupcopies, for example. In certain embodiments, archive copies may be madeand kept for extended periods in order to meet compliance regulations.

Moreover, when primary data 112 is archived, in some cases the archivedprimary data 112 or a portion thereof is deleted when creating thearchive copy. Thus, archiving can serve the purpose of freeing up spacein the primary storage device(s) 104. Similarly, when a secondary copy116 is archived, the secondary copy 116 may be deleted, and an archivecopy can therefore serve the purpose of freeing up space in secondarystorage device(s) 108. In contrast, source copies often remain intactwhen creating backup copies.

Snapshot Operations

Snapshot operations can provide a relatively lightweight, efficientmechanism for protecting data. From an end-user viewpoint, a snapshotmay be thought of as an “instant” image of the primary data 112 at agiven point in time. In one embodiment, a snapshot may generally capturethe directory structure of an object in primary data 112 such as a fileor volume or other data set at a particular moment in time and may alsopreserve file attributes and contents. A snapshot in some cases iscreated relatively quickly, e.g., substantially instantly, using aminimum amount of file space, but may still function as a conventionalfile system backup.

A snapshot copy in many cases can be made quickly and withoutsignificantly impacting primary computing resources because largeamounts of data need not be copied or moved. In some embodiments, asnapshot may exist as a virtual file system, parallel to the actual filesystem. Users in some cases gain read-only access to the record of filesand directories of the snapshot. By electing to restore primary data 112from a snapshot taken at a given point in time, users may also returnthe current file system to the state of the file system that existedwhen the snapshot was taken.

Some types of snapshots do not actually create another physical copy ofall the data as it existed at the particular point in time, but maysimply create pointers that are able to map files and directories tospecific memory locations (e.g., disk blocks) where the data resides, asit existed at the particular point in time. For example, a snapshot copymay include a set of pointers derived from the file system or anapplication. Each pointer points to a respective stored data block, socollectively, the set of pointers reflect the storage location and stateof the data object (e.g., file(s) or volume(s) or data set(s)) at aparticular point in time when the snapshot copy was created.

In some embodiments, once a snapshot has been taken, subsequent changesto the file system typically do not overwrite the blocks in use at thetime of the snapshot. Therefore, the initial snapshot may use only asmall amount of disk space needed to record a mapping or other datastructure representing or otherwise tracking the blocks that correspondto the current state of the file system. Additional disk space isusually required only when files and directories are actually modifiedlater. Furthermore, when files are modified, typically only the pointerswhich map to blocks are copied, not the blocks themselves. In someembodiments, for example in the case of “copy-on-write” snapshots, whena block changes in primary storage, the block is copied to secondarystorage or cached in primary storage before the block is overwritten inprimary storage. The snapshot mapping of file system data is alsoupdated to reflect the changed block(s) at that particular point intime. In some other cases, a snapshot includes a full physical copy ofall or substantially all of the data represented by the snapshot.Further examples of snapshot operations are provided in U.S. Pat. No.7,529,782, which is incorporated by reference herein.

Replication Operations

Another type of secondary copy operation is a replication operation.Some types of secondary copies 116 are used to periodically captureimages of primary data 112 at particular points in time (e.g., backups,archives, and snapshots). However, it can also be useful for recoverypurposes to protect primary data 112 in a more continuous fashion, byreplicating the primary data 112 substantially as changes occur. In somecases a replication copy can be a mirror copy, for instance, wherechanges made to primary data 112 are mirrored to another location (e.g.,to secondary storage device(s) 108). By copying each write operation tothe replication copy, two storage systems are kept synchronized orsubstantially synchronized so that they are virtually identical atapproximately the same time. Where entire disk volumes are mirrored,however, mirroring can require significant amount of storage space andutilizes a large amount of processing resources.

According to some embodiments storage operations are performed onreplicated data that represents a recoverable state, or “known goodstate” of a particular application running on the source system. Forinstance, in certain embodiments, known good replication copies may beviewed as copies of primary data 112. This feature allows the system todirectly access, copy, restore, backup or otherwise manipulate thereplication copies as if the data was the “live”, primary data 112. Thiscan reduce access time, storage utilization, and impact on sourceapplications 110, among other benefits.

Based on known good state information, the information management system100 can replicate sections of application data that represent arecoverable state rather than rote copying of blocks of data. Examplesof compatible replication operations (e.g., continuous data replication)are provided in U.S. Pat. No. 7,617,262, which is incorporated byreference herein.

Deduplication/Single-Instancing Operations

Another type of data movement operation is deduplication, which isuseful to reduce the amount of data within the system. For instance,some or all of the above-described secondary storage operations caninvolve deduplication in some fashion. New data is read, broken downinto blocks (e.g., sub-file level blocks) of a selected granularity,compared with blocks that are already stored, and only the new blocksare stored. Blocks that already exist are represented as pointers to thealready stored data.

In order to stream-line the comparison process, the informationmanagement system 100 may calculate and/or store signatures (e.g.,hashes) corresponding to the individual data blocks and compare thehashes instead of comparing entire data blocks. In some cases, only asingle instance of each element is stored, and deduplication operationsmay therefore be referred to interchangeably as “single-instancing”operations. Depending on the implementation, however, deduplication orsingle-instancing operations can store more than one instance of certaindata blocks, but nonetheless significantly reduce data redundancy.Moreover, single-instancing in some cases is distinguished fromdeduplication as a process of analyzing and reducing data at the filelevel, rather than the sub-file level.

Depending on the embodiment, deduplication blocks can be of fixed orvariable length. Using variable length blocks can provide enhanceddeduplication by responding to changes in the data stream, but caninvolve complex processing. In some cases, the information managementsystem 100 utilizes a technique for dynamically aligning deduplicationblocks (e.g., fixed-length blocks) based on changing content in the datastream, as described in U.S. Pat. No. 8,364,652, which is incorporatedby reference herein.

The information management system 100 can perform deduplication in avariety of manners at a variety of locations in the informationmanagement system 100. For instance, in some embodiments, theinformation management system 100 implements “target-side” deduplicationby deduplicating data (e.g., secondary copies 116) stored in thesecondary storage devices 108. In some such cases, the media agents 144are generally configured to manage the deduplication process. Forinstance, one or more of the media agents 144 maintain a correspondingdeduplication database that stores deduplication information (e.g.,datablock signatures). Examples of such a configuration are provided inU.S. Pat. Pub. No. 2012/0150826, which is incorporated by referenceherein. Deduplication can also be performed on the “source-side” (or“client-side”), e.g., to reduce the amount of traffic between the mediaagents 144 and the client computing device(s) 102 and/or reduceredundant data stored in the primary storage devices 104. Examples ofsuch deduplication techniques are provided in U.S. Pat. Pub. No.2012/0150818, which is incorporated by reference herein.

Information Lifecycle Management and Hierarchical Storage ManagementOperations

In some embodiments, files and other data over their lifetime move frommore expensive, quick access storage to less expensive, slower accessstorage. Operations associated with moving data through various tiers ofstorage are sometimes referred to as information lifecycle management(ILM) operations.

One type of ILM operation is a hierarchical storage management (HSM)operation. A HSM operation is generally an operation for automaticallymoving data between classes of storage devices, such as betweenhigh-cost and low-cost storage devices. For instance, an HSM operationmay involve movement of data from primary storage devices 104 tosecondary storage devices 108, or between tiers of secondary storagedevices 108. With each tier, the storage devices may be progressivelyrelatively cheaper, have relatively slower access/restore times, etc.For example, movement of data between tiers may occur as data becomesless important over time.

In some embodiments, an HSM operation is similar to an archive operationin that creating an HSM copy may (though not always) involve deletingsome of the source data. For example, an HSM copy may include data fromprimary data 112 or a secondary copy 116 that is larger than a givensize threshold or older than a given age threshold and that is stored ina backup format.

Often, and unlike some types of archive copies, HSM data that is removedor aged from the source copy is replaced by a logical reference pointeror stub. The reference pointer or stub can be stored in the primarystorage device 104 to replace the deleted data in primary data 112 (orother source copy) and to point to or otherwise indicate the newlocation in a secondary storage device 108.

According to one example, files are generally moved between higher andlower cost storage depending on how often the files are accessed. When auser requests access to the HSM data that has been removed or migrated,the information management system 100 uses the stub to locate the dataand often make recovery of the data appear transparent, even though theHSM data may be stored at a location different from the remaining sourcedata. The stub may also include some metadata associated with thecorresponding data, so that a file system and/or application can providesome information about the data object and/or a limited-functionalityversion (e.g., a preview) of the data object.

An HSM copy may be stored in a format other than the native applicationformat (e.g., where the data is compressed, encrypted, deduplicated,and/or otherwise modified from the original application format). In somecases, copies which involve the removal of data from source storage andthe maintenance of stub or other logical reference information on sourcestorage may be referred to generally as “on-line archive copies”. On theother hand, copies which involve the removal of data from source storagewithout the maintenance of stub or other logical reference informationon source storage may be referred to as “off-line archive copies”.

Auxiliary Copy and Disaster Recovery Operations

An auxiliary copy is generally a copy operation in which a copy iscreated of an existing secondary copy 116. For instance, an initial or“primary” secondary copy 116 may be generated using or otherwise bederived from primary data 112, whereas an auxiliary copy is generatedfrom the initial secondary copy 116. Auxiliary copies can be used tocreate additional standby copies of data and may reside on differentsecondary storage devices 108 than initial secondary copies 116. Thus,auxiliary copies can be used for recovery purposes if initial secondarycopies 116 become unavailable. Exemplary compatible auxiliary copytechniques are described in further detail in U.S. Pat. No. 8,230,195,which is incorporated by reference herein.

The information management system 100 may also perform disaster recoveryoperations that make or retain disaster recovery copies, often assecondary, high-availability disk copies. The information managementsystem 100 may create secondary disk copies and store the copies atdisaster recovery locations using auxiliary copy or replicationoperations, such as continuous data replication technologies. Dependingon the particular data protection goals, disaster recovery locations canbe remote from the client computing devices 102 and primary storagedevices 104, remote from some or all of the secondary storage devices108, or both.

Data Processing and Manipulation Operations

As indicated, the information management system 100 can also beconfigured to implement certain data manipulation operations, whichaccording to certain embodiments are generally operations involving theprocessing or modification of stored data. Some data manipulationoperations include content indexing operations and classificationoperations can be useful in leveraging the data under management toprovide enhanced search and other features. Other data manipulationoperations such as compression and encryption can provide data reductionand security benefits, respectively.

Data manipulation operations can be different than data movementoperations in that they do not necessarily involve the copying,migration or other transfer of data (e.g., primary data 112 or secondarycopies 116) between different locations in the system. For instance,data manipulation operations may involve processing (e.g., offlineprocessing) or modification of already stored primary data 112 and/orsecondary copies 116. However, in some embodiments data manipulationoperations are performed in conjunction with data movement operations.As one example, the information management system 100 may encrypt datawhile performing an archive operation.

Content Indexing

In some embodiments, the information management system 100 “contentindexes” data stored within the primary data 112 and/or secondary copies116, providing enhanced search capabilities for data discovery and otherpurposes. The content indexing can be used to identify files or otherdata objects having pre-defined content (e.g., user-defined keywords orphrases), metadata (e.g., email metadata such as “to”, “from”, “cc”,“bcc”, attachment name, received time, etc.).

The information management system 100 generally organizes and cataloguesthe results in a content index, which may be stored within the mediaagent database 152, for example. The content index can also include thestorage locations of (or pointer references to) the indexed data in theprimary data 112 or secondary copies 116, as appropriate. The resultsmay also be stored, in the form of a content index database orotherwise, elsewhere in the information management system 100 (e.g., inthe primary storage devices 104, or in the secondary storage device108). Such index data provides the storage manager 140 or anothercomponent with an efficient mechanism for locating primary data 112and/or secondary copies 116 of data objects that match particularcriteria.

For instance, search criteria can be specified by a user through userinterface 158 of the storage manager 140. In some cases, the informationmanagement system 100 analyzes data and/or metadata in secondary copies116 to create an “off-line” content index, without significantlyimpacting the performance of the client computing devices 102. Dependingon the embodiment, the system can also implement “on-line” contentindexing, e.g., of primary data 112. Examples of compatible contentindexing techniques are provided in U.S. Pat. No. 8,170,995, which isincorporated by reference herein.

Classification Operations—Metabase

In order to help leverage the data stored in the information managementsystem 100, one or more components can be configured to scan data and/orassociated metadata for classification purposes to populate a metabaseof information. Such scanned, classified data and/or metadata may beincluded in a separate database and/or on a separate storage device fromprimary data 112 (and/or secondary copies 116), such that metabaserelated operations do not significantly impact performance on othercomponents in the information management system 100.

In other cases, the metabase(s) may be stored along with primary data112 and/or secondary copies 116. Files or other data objects can beassociated with user-specified identifiers (e.g., tag entries) in themedia agent 144 (or other indices) to facilitate searches of stored dataobjects. Among a number of other benefits, the metabase can also allowefficient, automatic identification of files or other data objects toassociate with secondary copy or other information management operations(e.g., in lieu of scanning an entire file system). Examples ofcompatible metabases and data classification operations are provided inU.S. Pat. Nos. 8,229,954 and 7,747,579, which are incorporated byreference herein.

Encryption Operations

The information management system 100 in some cases is configured toprocess data (e.g., files or other data objects, secondary copies 116,etc.), according to an appropriate encryption algorithm (e.g., Blowfish,Advanced Encryption Standard [AES], Triple Data Encryption Standard[3-DES], etc.) to limit access and provide data security in theinformation management system 100.

The information management system 100 in some cases encrypts the data atthe client level, such that the client computing devices 102 (e.g., thedata agents 142) encrypt the data prior to forwarding the data to othercomponents, e.g., before sending the data media agents 144 during asecondary copy operation. In such cases, the client computing device 102may maintain or have access to an encryption key or passphrase fordecrypting the data upon restore. Encryption can also occur whencreating copies of secondary copies, e.g., when creating auxiliarycopies. In yet further embodiments, the secondary storage devices 108can implement built-in, high performance hardware encryption.

Management Operations

Certain embodiments leverage the integrated, ubiquitous nature of theinformation management system 100 to provide useful system-widemanagement functions. As two non-limiting examples, the informationmanagement system 100 can be configured to implement operationsmanagement and e-discovery functions.

Operations management can generally include monitoring and managing thehealth and performance of information management system 100 by, withoutlimitation, performing error tracking, generating granularstorage/performance metrics (e.g., job success/failure information,deduplication efficiency, etc.), generating storage modeling and costinginformation, and the like.

Such information can be provided to users via the user interface 158 ina single, integrated view. For instance, the integrated user interface158 can include an option to show a “virtual view” of the system thatgraphically depicts the various components in the system usingappropriate icons. The operations management functionality canfacilitate planning and decision-making. For example, in someembodiments, a user may view the status of some or all jobs as well asthe status of each component of the information management system 100.Users may then plan and make decisions based on this data. For instance,a user may view high-level information regarding storage operations forthe information management system 100, such as job status, componentstatus, resource status (e.g., network pathways, etc.), and otherinformation. The user may also drill down or use other means to obtainmore detailed information regarding a particular component, job, or thelike.

In some cases the information management system 100 alerts a user suchas a system administrator when a particular resource is unavailable orcongested. For example, a particular primary storage device 104 orsecondary storage device 108 might be full or require additionalcapacity. Or a component may be unavailable due to hardware failure,software problems, or other reasons. In response, the informationmanagement system 100 may suggest solutions to such problems when theyoccur (or provide a warning prior to occurrence). For example, thestorage manager 140 may alert the user that a secondary storage device108 is full or otherwise congested. The storage manager 140 may thensuggest, based on job and data storage information contained in itsdatabase 146, an alternate secondary storage device 108.

Other types of corrective actions may include suggesting an alternatedata path to a particular primary or secondary storage device 104, 108,or dividing data to be stored among various available primary orsecondary storage devices 104, 108 as a load balancing measure or tootherwise optimize storage or retrieval time. Such suggestions orcorrective actions may be performed automatically, if desired. Furtherexamples of some compatible operations management techniques and ofinterfaces providing an integrated view of an information managementsystem are provided in U.S. Pat. No. 7,343,453, which is incorporated byreference herein. In some embodiments, the storage manager 140implements the operations management functions described herein.

The information management system 100 can also be configured to performsystem-wide e-discovery operations in some embodiments. In general,e-discovery operations provide a unified collection and searchcapability for data in the system, such as data stored in the secondarystorage devices 108 (e.g., backups, archives, or other secondary copies116). For example, the information management system 100 may constructand maintain a virtual repository for data stored in the informationmanagement system 100 that is integrated across source applications 110,different storage device types, etc. According to some embodiments,e-discovery utilizes other techniques described herein, such as dataclassification and/or content indexing.

Information Management Policies

As indicated previously, an information management policy 148 caninclude a data structure or other information source that specifies aset of parameters (e.g., criteria and rules) associated with secondarycopy or other information management operations.

One type of information management policy 148 is a storage policy.According to certain embodiments, a storage policy generally comprises alogical container that defines (or includes information sufficient todetermine) one or more of the following items: (1) what data will beassociated with the storage policy; (2) a destination to which the datawill be stored; (3) datapath information specifying how the data will becommunicated to the destination; (4) the type of storage operation to beperformed; and (5) retention information specifying how long the datawill be retained at the destination.

Data associated with a storage policy can be logically organized intogroups, which can be referred to as “sub-clients”. A sub-client mayrepresent static or dynamic associations of portions of a data volume.Sub-clients may represent mutually exclusive portions. Thus, in certainembodiments, a portion of data may be given a label and the associationis stored as a static entity in an index, database or other storagelocation.

Sub-clients may also be used as an effective administrative scheme oforganizing data according to data type, department within theenterprise, storage preferences, or the like. Depending on theconfiguration, sub-clients can correspond to files, folders, virtualmachines, databases, etc. In one exemplary scenario, an administratormay find it preferable to separate e-mail data from financial data usingtwo different sub-clients.

A storage policy can define where data is stored by specifying a targetor destination storage device (or group of storage devices). Forinstance, where the secondary storage device 108 includes a group ofdisk libraries, the storage policy may specify a particular disk libraryfor storing the sub-clients associated with the policy. As anotherexample, where the secondary storage devices 108 include one or moretape libraries, the storage policy may specify a particular tape libraryfor storing the sub-clients associated with the storage policy, and mayalso specify a drive pool and a tape pool defining a group of tapedrives and a group of tapes, respectively, for use in storing thesub-client data.

Datapath information can also be included in the storage policy. Forinstance, the storage policy may specify network pathways and componentsto utilize when moving the data to the destination storage device(s). Insome embodiments, the storage policy specifies one or more media agents144 for conveying data (e.g., one or more sub-clients) associated withthe storage policy between the source (e.g., one or more host clientcomputing devices 102) and destination (e.g., a particular targetsecondary storage device 108).

A storage policy can also specify the type(s) of operations associatedwith the storage policy, such as a backup, archive, snapshot, auxiliarycopy, or the like. Retention information can specify how long the datawill be kept, depending on organizational needs (e.g., a number of days,months, years, etc.)

The information management policies 148 may also include one or morescheduling policies specifying when and how often to perform operations.Scheduling information may specify with what frequency (e.g., hourly,weekly, daily, event-based, etc.) or under what triggering conditionssecondary copy or other information management operations will takeplace. Scheduling policies in some cases are associated with particularcomponents, such as particular sub-clients, client computing device 102,and the like. In one configuration, a separate scheduling policy ismaintained for particular sub-clients on a client computing device 102.The scheduling policy specifies that those sub-clients are to be movedto secondary storage devices 108 every hour according to storagepolicies associated with the respective sub-clients.

When adding a new client computing device 102, administrators canmanually configure information management policies 148 and/or othersettings, e.g., via the user interface 158. However, this can be aninvolved process resulting in delays, and it may be desirable to begindata protecting operations quickly.

Thus, in some embodiments, the information management system 100automatically applies a default configuration to client computing device102. As one example, when a data agent(s) 142 is installed on a clientcomputing devices 102, the installation script may register the clientcomputing device 102 with the storage manager 140, which in turn appliesthe default configuration to the new client computing device 102. Inthis manner, data protection operations can begin substantiallyimmediately. The default configuration can include a default storagepolicy, for example, and can specify any appropriate informationsufficient to begin data protection operations. This can include a typeof data protection operation, scheduling information, a target secondarystorage device 108, data path information (e.g., a particular mediaagent 144), and the like.

Other types of information management policies 148 are possible. Forinstance, the information management policies 148 can also include oneor more audit or security policies. An audit policy is a set ofpreferences, rules and/or criteria that protect sensitive data in theinformation management system 100. For example, an audit policy maydefine “sensitive objects” as files or objects that contain particularkeywords (e.g. “confidential,” or “privileged”) and/or are associatedwith particular keywords (e.g., in metadata) or particular flags (e.g.,in metadata identifying a document or email as personal, confidential,etc.).

An audit policy may further specify rules for handling sensitiveobjects. As an example, an audit policy may require that a reviewerapprove the transfer of any sensitive objects to a cloud storage site,and that if approval is denied for a particular sensitive object, thesensitive object should be transferred to a local storage device 104instead. To facilitate this approval, the audit policy may furtherspecify how a secondary storage computing device 106 or other systemcomponent should notify a reviewer that a sensitive object is slated fortransfer.

In some implementations, the information management policies 148 mayinclude one or more provisioning policies. A provisioning policy caninclude a set of preferences, priorities, rules, and/or criteria thatspecify how clients 102 (or groups thereof) may utilize systemresources, such as available storage on cloud storage and/or networkbandwidth. A provisioning policy specifies, for example, data quotas forparticular client computing devices 102 (e.g. a number of gigabytes thatcan be stored monthly, quarterly or annually). The storage manager 140or other components may enforce the provisioning policy. For instance,the media agents 144 may enforce the policy when transferring data tosecondary storage devices 108. If a client computing device 102 exceedsa quota, a budget for the client computing device 102 (or associateddepartment) is adjusted accordingly or an alert may trigger.

While the above types of information management policies 148 have beendescribed as separate policies, one or more of these can be generallycombined into a single information management policy 148. For instance,a storage policy may also include or otherwise be associated with one ormore scheduling, audit, or provisioning policies. Moreover, whilestorage policies are typically associated with moving and storing data,other policies may be associated with other types of informationmanagement operations. The following is a non-exhaustive list of itemsthe information management policies 148 may specify:

-   -   schedules or other timing information, e.g., specifying when        and/or how often to perform information management operations;    -   the type of secondary copy 116 and/or secondary copy format        (e.g., snapshot, backup, archive, HSM, etc.);    -   a location or a class or quality of storage for storing        secondary copies 116 (e.g., one or more particular secondary        storage devices 108);    -   preferences regarding whether and how to encrypt, compress,        deduplicate, or otherwise modify or transform secondary copies        116;    -   which system components and/or network pathways (e.g., preferred        media agents 144) should be used to perform secondary storage        operations;    -   resource allocation between different computing devices or other        system components used in performing information management        operations (e.g., bandwidth allocation, available storage        capacity, etc.);    -   whether and how to synchronize or otherwise distribute files or        other data objects across multiple computing devices or hosted        services; and    -   retention information specifying the length of time primary data        112 and/or secondary copies 116 should be retained, e.g., in a        particular class or tier of storage devices, or within the        information management system 100.

Policies can additionally specify or depend on a variety of historicalor current criteria that may be used to determine which rules to applyto a particular data object, system component, or information managementoperation, such as:

-   -   frequency with which primary data 112 or a secondary copy 116 of        a data object or metadata has been or is predicted to be used,        accessed, or modified;    -   time-related factors (e.g., aging information such as time since        the creation or modification of a data object);    -   deduplication information (e.g., hashes, data blocks,        deduplication block size, deduplication efficiency or other        metrics);    -   an estimated or historic usage or cost associated with different        components (e.g., with secondary storage devices 108);    -   the identity of users, applications 110, client computing        devices 102 and/or other computing devices that created,        accessed, modified, or otherwise utilized primary data 112 or        secondary copies 116;    -   a relative sensitivity (e.g., confidentiality) of a data object,        e.g., as determined by its content and/or metadata;    -   the current or historical storage capacity of various storage        devices;    -   the current or historical network capacity of network pathways        connecting various components within the storage operation cell;    -   access control lists or other security information; and    -   the content of a particular data object (e.g., its textual        content) or of metadata associated with the data object.        Exemplary Storage Policy and Secondary Storage Operations

FIG. 1E shows a data flow data diagram depicting performance of storageoperations by an embodiment of an information management system 100,according to an exemplary data storage policy 148A. The informationmanagement system 100 includes a storage manger 140, a client computingdevice 102 having a file system data agent 142A and an email data agent142B residing thereon, a primary storage device 104, two media agents144A, 144B, and two secondary storage devices 108A, 108B: a disk library108A and a tape library 108B. As shown, the primary storage device 104includes primary data 112A, 1128 associated with a file systemsub-client and an email sub-client, respectively.

As indicated by the dashed box, the second media agent 144B and the tapelibrary 108B are “off-site”, and may therefore be remotely located fromthe other components in the information management system 100 (e.g., ina different city, office building, etc.). In this manner, informationstored on the tape library 1088 may provide protection in the event of adisaster or other failure.

The file system sub-client and its associated primary data 112A incertain embodiments generally comprise information generated by the filesystem and/or operating system of the client computing device 102, andcan include, for example, file system data (e.g., regular files, filetables, mount points, etc.), operating system data (e.g., registries,event logs, etc.), and the like. The e-mail sub-client, on the otherhand, and its associated primary data 112B, include data generated by ane-mail client application operating on the client computing device 102,and can include mailbox information, folder information, emails,attachments, associated database information, and the like. As describedabove, the sub-clients can be logical containers, and the data includedin the corresponding primary data 112A, 112B may or may not be storedcontiguously.

The exemplary storage policy 148A includes a backup copy rule set 160, adisaster recovery copy rule set 162, and a compliance copy rule set 164.The backup copy rule set 160 specifies that it is associated with a filesystem sub-client 166 and an email sub-client 168. Each of thesesub-clients 166, 168 are associated with the particular client computingdevice 102. The backup copy rule set 160 further specifies that thebackup operation will be written to the disk library 108A, anddesignates a particular media agent 144A to convey the data to the disklibrary 108A. Finally, the backup copy rule set 160 specifies thatbackup copies created according to the rule set 160 are scheduled to begenerated on an hourly basis and to be retained for 30 days. In someother embodiments, scheduling information is not included in the storagepolicy 148A, and is instead specified by a separate scheduling policy.

The disaster recovery copy rule set 162 is associated with the same twosub-clients 166, 168. However, the disaster recovery copy rule set 162is associated with the tape library 108B, unlike the backup copy ruleset 160. Moreover, the disaster recovery copy rule set 162 specifiesthat a different media agent 144B than the media agent 144A associatedwith the backup copy rule set 160 will be used to convey the data to thetape library 108B. As indicated, disaster recovery copies createdaccording to the rule set 162 will be retained for 60 days, and will begenerated on a daily basis. Disaster recovery copies generated accordingto the disaster recovery copy rule set 162 can provide protection in theevent of a disaster or other data-loss event that would affect thebackup copy 116A maintained on the disk library 108A.

The compliance copy rule set 164 is only associated with the emailsub-client 166, and not the file system sub-client 168. Compliancecopies generated according to the compliance copy rule set 164 willtherefore not include primary data 112A from the file system sub-client166. For instance, the organization may be under an obligation to storemaintain copies of email data for a particular period of time (e.g., 10years) to comply with state or federal regulations, while similarregulations do not apply to the file system data. The compliance copyrule set 164 is associated with the same tape library 108B and mediaagent 144B as the disaster recovery copy rule set 162, although adifferent storage device or media agent could be used in otherembodiments. Finally, the compliance copy rule set 164 specifies thatcopies generated under the compliance copy rule set 164 will be retainedfor 10 years, and will be generated on a quarterly basis.

At step 1, the storage manager 140 initiates a backup operationaccording to the backup copy rule set 160. For instance, a schedulingservice running on the storage manager 140 accesses schedulinginformation from the backup copy rule set 160 or a separate schedulingpolicy associated with the client computing device 102, and initiates abackup copy operation on an hourly basis. Thus, at the scheduled timeslot the storage manager 140 sends instructions to the client computingdevice 102 to begin the backup operation.

At step 2, the file system data agent 142A and the email data agent 142Bresiding on the client computing device 102 respond to the instructionsreceived from the storage manager 140 by accessing and processing theprimary data 112A, 112B involved in the copy operation from the primarystorage device 104. Because the operation is a backup copy operation,the data agent(s) 142A, 142B may format the data into a backup format orotherwise process the data.

At step 3, the client computing device 102 communicates the retrieved,processed data to the first media agent 144A, as directed by the storagemanager 140, according to the backup copy rule set 160. In some otherembodiments, the information management system 100 may implement aload-balancing, availability-based, or other appropriate algorithm toselect from the available set of media agents 144A, 144B. Regardless ofthe manner the media agent 144A is selected, the storage manager 140 mayfurther keep a record in the storage manager database 140 of theassociation between the selected media agent 144A and the clientcomputing device 102 and/or between the selected media agent 144A andthe backup copy 116A.

The target media agent 144A receives the data from the client computingdevice 102, and at step 4 conveys the data to the disk library 108A tocreate the backup copy 116A, again at the direction of the storagemanager 140 and according to the backup copy rule set 160. The secondarystorage device 108A can be selected in other ways. For instance, themedia agent 144A may have a dedicated association with a particularsecondary storage device(s), or the storage manager 140 or media agent144A may select from a plurality of secondary storage devices, e.g.,according to availability, using one of the techniques described in U.S.Pat. No. 7,246,207, which is incorporated by reference herein.

The media agent 144A can also update its index 153 to include dataand/or metadata related to the backup copy 116A, such as informationindicating where the backup copy 116A resides on the disk library 108A,data and metadata for cache retrieval, etc. After the 30 day retentionperiod expires, the storage manager 140 instructs the media agent 144Ato delete the backup copy 116A from the disk library 108A.

At step 5, the storage manager 140 initiates the creation of a disasterrecovery copy 1166 according to the disaster recovery copy rule set 162.For instance, at step 6, based on instructions received from the storagemanager 140 at step 5, the specified media agent 144B retrieves the mostrecent backup copy 116A from the disk library 108A.

At step 7, again at the direction of the storage manager 140 and asspecified in the disaster recovery copy rule set 162, the media agent144B uses the retrieved data to create a disaster recovery copy 116B onthe tape library 108B. In some cases, the disaster recovery copy 1166 isa direct, mirror copy of the backup copy 116A, and remains in the backupformat. In other embodiments, the disaster recovery copy 116C may begenerated in some other manner, such as by using the primary data 112A,1126 from the storage device 104 as source data. The disaster recoverycopy operation is initiated once a day and the disaster recovery copies116A are deleted after 60 days.

At step 8, the storage manager 140 initiates the creation of acompliance copy 116C, according to the compliance copy rule set 164. Forinstance, the storage manager 140 instructs the media agent 144B tocreate the compliance copy 116C on the tape library 108B at step 9, asspecified in the compliance copy rule set 164. In the example, thecompliance copy 116C is generated using the disaster recovery copy 116B.In other embodiments, the compliance copy 116C is instead generatedusing either the primary data 112B corresponding to the email sub-clientor using the backup copy 116A from the disk library 108A as source data.As specified, compliance copies 116C are created quarterly, and aredeleted after ten years.

While not shown in FIG. 1E, at some later point in time, a restoreoperation can be initiated involving one or more of the secondary copies116A, 1166, 116C. As one example, a user may manually initiate a restoreof the backup copy 116A by interacting with the user interface 158 ofthe storage manager 140. The storage manager 140 then accesses data inits index 150 (and/or the respective storage policy 148A) associatedwith the selected backup copy 116A to identify the appropriate mediaagent 144A and/or secondary storage device 116A.

In other cases, a media agent may be selected for use in the restoreoperation based on a load balancing algorithm, an availability basedalgorithm, or other criteria. The selected media agent 144A retrievesthe data from the disk library 108A. For instance, the media agent 144Amay access its index 153 to identify a location of the backup copy 116Aon the disk library 108A, or may access location information residing onthe disk 108A itself.

When the backup copy 116A was recently created or accessed, the mediaagent 144A accesses a cached version of the backup copy 116A residing inthe media agent index 153, without having to access the disk library108A for some or all of the data. Once it has retrieved the backup copy116A, the media agent 144A communicates the data to the source clientcomputing device 102. Upon receipt, the file system data agent 142A andthe email data agent 142B may unpackage (e.g., restore from a backupformat to the native application format) the data in the backup copy116A and restore the unpackaged data to the primary storage device 104.

Exemplary Secondary Copy Formatting

The formatting and structure of secondary copies 116 can vary, dependingon the embodiment. In some cases, secondary copies 116 are formatted asa series of logical data units or “chunks” (e.g., 512 MB, 1 GB, 2 GB, 4GB, or 8 GB chunks). This can facilitate efficient communication andwriting to secondary storage devices 108, e.g., according to resourceavailability. For example, a single secondary copy 116 may be written ona chunk-by-chunk basis to a single secondary storage device 108 oracross multiple secondary storage devices 108. In some cases, users canselect different chunk sizes, e.g., to improve throughput to tapestorage devices.

Generally, each chunk can include a header and a payload. The payloadcan include files (or other data units) or subsets thereof included inthe chunk, whereas the chunk header generally includes metadata relatingto the chunk, some or all of which may be derived from the payload. Forexample, during a secondary copy operation, the media agent 144, storagemanager 140, or other component may divide the associated files intochunks and generate headers for each chunk by processing the constituentfiles.

The headers can include a variety of information such as fileidentifier(s), volume(s), offset(s), or other information associatedwith the payload data items, a chunk sequence number, etc. Importantly,in addition to being stored with the secondary copy 116 on the secondarystorage device 108, the chunk headers can also be stored to the index153 of the associated media agent(s) 144 and/or the storage managerindex 150. This is useful in some cases for providing faster processingof secondary copies 116 during restores or other operations. In somecases, once a chunk is successfully transferred to a secondary storagedevice 108, the secondary storage device 108 returns an indication ofreceipt, e.g., to the media agent 144 and/or storage manager 140, whichmay update their respective indexes 150, 153 accordingly.

During restore, chunks may be processed (e.g., by the media agent 144)according to the information in the chunk header to reassemble thefiles. Additional information relating to chunks can be found in U.S.Pat. No. 8,156,086, which is incorporated by reference herein.

System Overview

The systems and methods described with respect to FIGS. 1A-1E can beused to implement automated retention policy. In some embodiments, atiered retention module is a software module that forms a part of orresides on the storage manager 140 or, alternatively, the media agents144. The tiered retention module can additionally be a software moduleexecuting on one or more of the client computers 102. In someembodiments, the tiered retention module may be implemented as a part ofthe data agent 142. Automated retention policies will now be discussedin more detail with respect to FIGS. 2-5.

FIG. 2 illustrates a block diagram of an exemplary network storagearchitecture compatible with embodiments described herein. The system200 is configured to perform storage operations on electronic data in acomputer network. As shown, the system 200 includes a storage manager210 and one or more of the following: a client 220, an information store230, a data agent 240, a tiered retention module 250, a media agent 270,and a storage device 280.

The system 200 and corresponding components of FIG. 2 may be similar toor the same as the system 100 and similarly named components of FIG. 1D.Moreover, depending on the embodiment, the system 200 of FIG. 2 mayadditionally include any of the other components shown in FIG. 1D thatare not specifically shown in FIG. 2 (e.g., one or more storage managerdatabases, one or more media agent databases, one or more storagemanager indexes, one or more media agent indexes, etc.). The system 200may include one or more of each component. All components of the system200 can be in direct communication with each other or communicateindirectly via the client 220, the storage manager 210, the media agent270, or the like. In certain embodiments, some of the components in FIG.2 shown as separate components can reside on a single computing device,or vice versa. For example, the tiered retention module 250 can be onthe storage manager 210 or on a separate computing device.

An automatic, tiered retention module 250 generally manages andclassifies data in the information store 230 and/or the storage devices280 according to a user-defined (or predefined) policy for retention indifferent buckets within the storage system 200. As will be described ingreater detail herein, the buckets can be logically organized in ahierarchy. Moreover, the bucket hierarchy 285 can be physicallydistributed across the various memory components in the storage system200. For instance, the buckets 285 can be implemented in one or more ofthe secondary storage devices 280. In some embodiments, the tieredretention module 250 is a software module that forms a part of orresides on the storage manager 110 or, alternatively, the media agents270. The tiered retention module 250 can additionally be a softwaremodule executing on one or more of the client computers 220. In someembodiments, the tiered retention module 250 may be implemented as apart of the data agent 240. The tiered retention module 250 will bediscussed in more detail with respect to FIGS. 3-5.

An Example Automatic, Tiered Retention Data Storage System

FIG. 3A is a data flow diagram illustrative of the interaction betweenthe various components of an exemplary storage system 200 configured toimplement automatic, tiered retention according to certain embodiments.As illustrated, the example tiered retention system 200 includes astorage manager 210, one or more clients 220, an information store 230,one or more data agents 240, a tiered retention module 250, one or moreapplications 260, one or more media agents 270, and one or more storagedevices 280. Although not shown, there may be a different informationstore 230 associated with each of the clients 220. As shown in FIG. 2,one or more clients 220 may communicate with one or more media agents270, and one or more media agents 270 may communicate with one or morestorage devices 280.

The system 200 and corresponding components of FIG. 3A may be similar toor the same as the system 100, 200 and similarly named components ofFIGS. 1D and 2. Moreover, depending on the embodiment, the system 200 ofFIG. 3A may additionally include any of the other components shown inFIG. 2 that are not specifically shown in FIG. 3A (e.g., one or moreinformation stores, etc.). The system 200 may include one or more ofeach component. All components of the system 200 can be in directcommunication with each other or communicate indirectly via the client220, the storage manager 210, the media agent, or the like. In certainembodiments, some of the components in FIG. 3A shown as separatecomponents can reside on a single computing device, or vice versa. Forexample, the tiered retention module 250 can be on the storage manager210 or on a separate computing device.

With further reference to FIG. 3A, the interaction between the variouscomponents of the automatic, tiered retention system will now bedescribed in greater detail with respect to data flow steps indicated bythe numbered arrows.

At data flow step 1, a tiered retention storage policy is received bythe storage manager 210. The policy can be defined by a systemadministrator or another user. Alternatively, the policy can bepreconfigured in the storage manager 210. For instance, the storagemanager 210 may access a default tiered retention policy if it does notreceive one from the user or other entity.

The tiered retention storage policy includes criteria for automaticallyclassifying data, such as user data stored in the info store 230 and/orin the storage devices 280. The classification criteria can depend onthe user's specific requirements, and the user can define itaccordingly. Details regarding automatic classification will bediscussed below in connection with data flow step 3.

At data flow step 2, data in the information store 230 is copied to thestorage devices 280. While described with respect to a backup copyoperation for the purposes of illustration, the techniques describedherein are compatible with other types of storage operations, such as,for example, replication, snapshots, archiving and the like. Adescription of some storage operations compatible with embodimentsdescribed herein is provided above. The data agents 240 can initiate thebackup of data through the media agents 270, and the media agents 270migrate or otherwise copy the data to the storage devices 280. One ormore data agents 240 may communicate with one or more media agent 270,and one or more media agents 270 may communicate with one or morestorage device 280. In certain embodiments, the data migrated to thestorage devices 280 is initially placed in the default tier in thestorage devices 280, which may be associated with a default retention(e.g., relatively short) period.

At data flow step 3, the tiered retention module 250 monitors data inthe storage devices 280, and, based on the results of the monitoring,automatically classifies the data according to the tiered retentionpolicy. Data in the storage devices 280 may be analyzed at anygranularity. For instance, the data can organized and/or processed asfiles (e.g., emails, Microsoft Office documents, media files, etc.),pages, which may span more than one file, data blocks, which maycorrespond to portions of files, or in any other appropriate fashion.

The retention policy may specify that the tiered retention module 250applies the retention policy (e.g., classifies, copies and/or prunes thedata) according to a desired schedule. For example, the system 200 mayrepeatedly apply the retention policy (e.g., classify, copy and/or prunethe data) after the passage of a pre-determined amount of time, such ason a regular basis (e.g., after a particular time interval, such as acertain number of hours or days), or on an intermittent basis. In someembodiments, the schedule dictates that the tiered retention module 250classifies and assigns data to appropriate buckets incrementally, as thedata is added to the system. In this manner, the classification and/orpruning can be applied to data as it is stored (e.g., onto the secondarystorage devices 280). As an example, the scheduling policy can dictatethat the tiered retention module 250 classify and or copy the data uponreceipt of a pre-determined amount of new data, such as where apre-determined amount of new backup data is stored on the storagedevices 280. In this case, classification into buckets may occur onnewly stored data only after receiving a threshold amount of new datasince the last incremental application of the classification process. Byclassifying the data in increments, new data items can be sortedefficiently without having to re-sort old data items. In some cases, thepolicy can comprise a combination of time-based and incrementalapproaches. For instance, in one embodiment, only newly stored data isclassified into buckets, while substantially all of the data is analyzedfor pruning. Even where classification generally occurs only onincremental data, upon implementation of a new retention policy,substantially all of the data may be initially classified into bucketsin order to recalibrate according to the new policy. In general,selection of an appropriate scheduling policy reduces manual processingby administrators, saving resources.

Based on the tiered retention policy, the tiered retention module 250can classify data based on a wide variety of parameters, includingcontent of the data, metadata associated with the data, or any otherappropriate characteristic or attribute of the data.

In one embodiment, the tiered retention module 250 searches through thedata based on certain (e.g., user-specified) search terms and classifiesthe data based on the results of the search. For instance, where thedata is organized in a plurality of files, the user specifies certainsearch terms, and the tiered retention module 250 searches through thecontent of the files, metadata associated with the files, or both. Thesearch can be a semantic search, concept search, or any other type ofenhanced search.

Where the files comprise emails, for example, the policy can classifydata according to email content, subject matter as indicated by contentand/or metadata, or parameters related to email. Email parameters caninclude mailbox owner, sender, receiver, date, etc. As an example, acorporation may define a tiered retention policy which dictates thatemails relating to financial documents are retained by the storagesystem 200 for a certain number of years, based on subject matter (e.g.,subject matter of content and/or metadata could indicate that the emailis associated with the accounting department of an organization). Asanother example, a retention policy may also dictate that emails sent toand/or received from a certain employee (e.g., the CEO) are stored for aparticular number of years. The tiered retention module 250 can identifysuch emails based on metadata indicating the mailbox owner, the senderor recipient email address, or some other appropriate means.

Multiple metadata properties may be used together, and metadataproperties could be used in conjunction with content. Metadata may bestored in a metabase, as described in greater detail in application Ser.No. 11/563,940, now U.S. Pat. No. 7,747,579, issued Jun. 29, 2010,herein incorporated by reference in its entirety.

Some example scenarios where the automatic classification describedherein may be particularly useful include the following:

-   -   A pharmaceutical company wants to track all emails discussing a        particular drug. The classification can be, for example, based        on a search of the subject matter or on a search of the email        content. All emails that are included in the search results are        retained for 7 years.    -   A corporation wants to retain all documents created or modified        in January 2012 for 5 years. The classification can be based on        metadata properties like time of creation or modification.    -   A company wants to keep all emails sent by the CEO for a period        of 5 years. The classification may be based on the sender's        email address.

The data that is classified according to a particular retention policyis assigned to a corresponding “bucket” in the storage system 200. Asused herein, the term “bucket” can refer to a data storage containerhaving a particular set of retention parameters associated with it.Retention parameters can include, without limitation (1) a retentionperiod defining a length of time data included in a particular bucket iskept until the data is pruned or otherwise deleted from the bucket, (2)a storage class or type (e.g., primary backup, secondary backup,archive, a particular tier in a hierarchical storage management system,etc.), (3) a type of media associated with the bucket (e.g., magneticdrive, tape drive, solid-state drive, etc.

Moreover, buckets can be delineated logically, physically, or acombination thereof. For example, a first set of one or more of thebuckets 285 may reside logically and physically on a first one of thestorage devices 280, a second set of one or more of the buckets 285 mayreside on a second one of the storage devices 280, and so on. In othercases, one or more of the buckets 285 may comprise a single logicalentity, but is distributed across more than one of the storage devices280. In yet further configurations, one or more of the storage devices280 correspond to a single bucket. In another embodiment, the bucketsare delineated by storage device type, and storage devices having afirst type correspond to a first bucket or set of buckets, storagedevices having a second type correspond to a second bucket or set ofbuckets, etc.

The retention period for the buckets can vary (e.g., 1, 2, 5, 10 or morehours, days or years). Moreover, the retention period can correspond tothe length of time the data will be kept after it is placed in thebucket, to the length of time the data will be kept after it wasoriginally created by an application 260 on the client 220 or stored inthe client information store 230, or to some other appropriate duration.After the time period expires, the tiered retention module 250 prunesthe data from the particular bucket. For instance, the data may bepruned at the next scheduled application of the pruning logic accordingto the retention policy. The time period can be set by the user (e.g.,at data flow step 1) in some cases, or can be part of a pre-determinedretention policy. In some cases, the tiered retention module 250 setsthe retention period based on some other characteristic associated withthe particular bucket. For example, the retention period can be based onthe type of data associated with the bucket (e.g., emails, finance oraccounting related files, etc.), the type of media associated with thebucket, and the like. In other embodiments, a default retention periodis used.

Buckets may also be defined based on criteria for adding data to abucket instead of or in addition to retention period. For instance,buckets may be associated with particular content and metadata.

As shown in FIG. 3A, the buckets 285 may be organized in a hierarchy incertain cases. For example, “parent” buckets at a first level in thehierarchy can each be further broken down into “child” buckets at lowerlevels in the hierarchy. And the files (or other data) can be assignedto the various buckets based on content, metadata, etc. For example,child buckets may generally have longer associated retention periodsthan the parent bucket from which they depend.

As an illustration, the retention policy may dictate that alluser-generated files associated with employees of a pharmaceuticalcompany be placed in a parent bucket having a 3-year retention period.The policy may further dictate that certain ones of the user-generatedfiles be further allocated amongst a plurality of child buckets havingdifferent (e.g., longer) retention periods than the parent bucket. Forinstance, any emails associated with a particular employee of anorganization (e.g., the Chief Executive Officer (“CEO”) or ChiefTechnical Officer (“CTO”)) may be assigned to a first child buckethaving a 7-year retention period. The tiered retention module 250 mayassign to the first child bucket any emails in that particularemployee's inbox, that were sent by that employee, that were received bythat employee, etc. Another child bucket having a 5-year retentionperiod may include any documents related to or referencing a particularbrand or type of medicine. Child buckets are described in greater detailbelow with respect to FIG. 5.

The parent bucket in certain embodiments includes all data in the childbucket, and logically, the child bucket can therefore be a subset of theparent bucket. In one embodiment, the parent bucket and the child bucketeach maintain separate copies of their respective data items. In anotherembodiment, only a single copy of the data item exists for the parentbucket and the child bucket, and the copy is not pruned until after thelonger of the parent and child retention periods expires. For instance,when the shorter of the parent and child retention periods expires, thetiered retention module 250 may determine whether or not the databelongs to another bucket before pruning the data. And, upon determiningthat the data belongs to a bucket having an unexpired retention period,the tiered retention module 250 decides not to prune that particulardata item.

As mentioned above, the storage devices 280 include one or more buckets285 that are each associated with a particular classification and havedifferent retention periods. And the buckets 285 in the storage devices280 can each have separate copies of data belonging to them. Forexample, if an email belongs in both the 3-year bucket and the 5-yearbucket, each bucket has a copy of the email so that the differentbuckets can operate and be managed substantially independently of otherbuckets. In one embodiment, the copies of at least some of the dataitems are pointers to the actual data. For instance, where deduplicationtechnology is used, the data items may comprise pointers to deduplicateddata blocks. In other embodiments, each bucket has actual copies of allof the data items rather than pointers. Particularly where the bucketsretain their own copies of the respective data items, the tieredretention module 250 can treat the buckets independently, which cansimplify processing. For instance, in such cases the system 200 cansimply prune data items from a bucket upon expiration of the retentionperiod, even if the same data item exists in another bucket. Thus, thecopy of the data in a bucket with a shorter retention period is removedfrom that bucket upon expiration of the retention period even if thatdata item it is also included in a bucket with a longer retentionperiod.

After the data is migrated to the corresponding buckets 285 in thestorage devices 280, the data may be content indexed to facilitatesearching of the data. The content index may be a common content indexfor the buckets having the same retention period. For example, a bucketcould include multiple buckets within it that are based on differentclassifications, such as CEO emails and financial documents, and thesystem 200 could have one content index for the entire bucket, insteadof having a content index for each bucket. Alternatively, each bucketbased on a classification could have a separate content index. In otherembodiments, data is not content indexed, and a user can navigatethrough the data by browsing. For example, the user can read through allCEO emails without using a particular tool.

As described above, the entire process of classifying, storing andpruning data based on content and/or metadata may be automatic from thecreation of the data item by the corresponding user application 260 topruning of the data item from the system 200. In particular, theclassification of data to store for different periods of time can beaccomplished automatically. In this way, the amount of data acorporation or an organization needs to maintain can be dramaticallyreduced and become more manageable. Moreover, the automated nature ofthe process avoids the manual search process involved in some existingdata retention solutions. This allows organizations to retain data in amanner that suits the needs of the organization while dedicating farfewer resources and expense to the data pruning process.

FIG. 3B is a data flow diagram illustrative of the interaction betweenthe various components of an exemplary storage system 200 configured toimplement automatic, tiered retention according to other embodiments. Incontrast to the arrangement shown in FIG. 3A, in the embodiment shown inFIG. 3B, the tiered retention module 250 resides on one or more of theclients 220.

At data flow step 1, the storage manager 210 accesses the tieredretention policy. For instance, the tiered retention policies may bepreconfigured policies that are stored in the storage manager 210, ormay be received by the storage manager 210 (e.g., via user input), asexplained with respect to FIG. 3A.

At data flow step 2, the storage manager 210 transmits the retentionpolicies and rules to the client(s) 220. In other embodiments, thepolicy is input at the client 220. Where there are multiple clients, thepolicies can be the same across all clients, or can instead beclient-specific and differ depending on the client.

As previously mentioned, the tiered retention module 250 may be asoftware module that resides on the client 220 or on a separatecomputing device. If on the client 220, the tiered retention module 250can be a standalone module or can be a part of the data agent 240.

At data flow step 3, the tiered retention module 250 monitors datagenerated by the applications 260, and, based on the results of themonitoring, automatically classifies the data according to the tieredretention policy. In some cases, the tiered retention module 250monitors the data after the data has been stored in the informationstore 230. For instance, the tiered retention module 250 may access thedata from the information store 230 and process the data according tothe retention policy. In other cases, the tiered retention module 250monitors the data before it is actually stored in the information store230. For instance, the tiered retention module 250 may perform asnooping function to intercept communications between the application(s)260 and the information store 230. In this manner, the tiered retentionmodule 250 can process the intercepted data without actually readingfrom the information store 230. In yet other configurations, the tieredretention module 250 obtains the data directly from the applications260.

The data in the information store 230 may be content indexed as itenters the system. Alternatively, the content indexing may be done at alater time.

At data flow step 4, the classified data is copied to the correspondingbucket in the storage system 200. For instance, the data agent 240 caninitiate the backup of data through media agents 270, which then conductthe data to the storage devices 280. Or the tiered retention module 250may interact with the media agents 270 and/or data agents to migrate thedata to the buckets 285. While described with respect to a backup copyoperation for the purposes of illustration, the techniques describedherein are compatible with other types of storage operations, such as,for example, replication, snapshots, archiving and the like. Adescription of some storage operations compatible with embodimentsdescribed herein is provided above.

FIG. 4 is a flow diagram illustrative of one embodiment of a routine 400implemented by an automatic, tiered retention storage system forimplementing an automatic retention policy. The routine 400 is describedwith respect to the system 200 of FIG. 3A. However, one or more of thesteps of routine 400 may be implemented by other tiered retentionstorage systems, such as those described in greater detail above withreference to FIGS. 2 and 3B. The routine 400 can be implemented by anyone, or a combination of, a client, a storage manager, a data agent, atiered retention module, a media agent, and the like. Moreover, furtherdetails regarding certain aspects of at least some of steps of theroutine 400 are described in greater detail above with reference toFIGS. 3A and 3B. Although described in relation to backup operations forthe purposes of illustration, the process of FIG. 4 can be compatiblewith other types of storage operations, such as, for example, migration,snapshots, replication operations, and the like.

At block 401, the system administrator or user creates a tieredretention policy to automatically classify data to be stored retained ina bucket, and the policy is received by the storage manager.Alternatively, the policies could be preconfigured and preloaded in thestorage manager. For instance, a default policy may reside at thestorage manager and be used if a user-defined storage policy is notreceived.

At block 402, the tiered retention module 250 according to someembodiments processes the data in the storage devices 280 and determineswhether the data should be placed in a particular bucket according tothe tiered retention policy. As discussed above, the processing of block402 can occur according to a scheduling policy, such as at apre-determined time increments (e.g., a pre-determined number of hours,days, etc.). Or the processing can occur based on some other triggeringevent, such as when a new tiered retention policy is activated, or aftera threshold amount of new, unclassified data is migrated to the storagedevices 280 which has not yet been classified by the tiered retentionmodule 250.

In other embodiments, such as in the configuration of FIG. 2B, thetiered retention module 250 resides on one or more clients, and thetiered retention module monitors the data in the information store 230.The tiered retention module 250 may monitor the data after it has beensaved to the information store, or before it is saved to the informationstore (e.g., by performing a snooping function).

If the tiered retention module determines that certain data belongs in atiered retention bucket(s), as shown in block 403, the data isautomatically assigned to the corresponding bucket(s), as shown in block404. In some embodiments, if the data does not belong in a particularbucket, the data is assigned to a default bucket, as shown in block 405.Once the data is assigned to a particular bucket (or buckets) at block404, an instance of the data is created for each assigned bucket, asshown in block 407. In other embodiments, where a data item belongs tomore than one bucket, only one physical copy of the data item isretained, and a pointer or other logical reference to the data item isretained for at least some of the buckets including the data item.

If it is determined that the retention period for a specific bucket ismet, as shown in block 408, the data instance in the bucket is prunedfrom the bucket at block 409. If data was assigned to the default bucketat block 405, the data instance for the data item is pruned at block 409if the default retention period is met, as shown in block 406. If allthe data in the bucket is pruned, the bucket itself may be deleted.

The routine 400 can include fewer, more, or different blocks than thoseillustrated in FIG. 4 without departing from the spirit and scope of thedescription. Moreover, it will be appreciated by those skilled in theart and others that some or all of the functions described in thisdisclosure may be embodied in software executed by one or moreprocessors of the disclosed components and mobile communication devices.The software may be persistently stored in any type of non-volatilestorage.

FIG. 5 is a schematic diagram illustrating a specific example of a datastorage system implementing a tiered retention policy defining aparticular retention hierarchy 500 including a plurality of buckets520-560. For example, the tiered retention hierarchy 500 shown in FIG. 5may be implemented by any the data storage systems described withrespect to FIGS. 2 and 3, or by some other data storage system.

In the example illustrated in FIG. 5, out of all company documents 510,Corporation A decides to store all CEO emails for 7 years. A systemadministrator or a user defines a tiered retention policy so that allemails with the CEO as the mailbox owner are stored for a term of atleast 7 years. Thus, the policy dictates that all emails having metadataindicating that the CEO is the mailbox owner is assigned to a “7-year”bucket 520 having a retention period of 7 years. The tiered retentionmodule 250 monitors data in the storage devices 280 according to thetiered retention policy (e.g., according to a time based schedule) anddetermines whether there are any data items to assign to the 7-yearbucket 520 defined by the policy. If certain emails meet the criteriafor the 7-year bucket 520, they are classified as CEO emails to retainfor 7 years and assigned to the 7-year bucket 520.

According to the policy above, all CEO emails are stored in the 7-yearbucket 520. However, even CEO emails may not all be of equal importance.Therefore, a multi-tiered retention scheme may be defined for CEOemails. For example, the company may want to keep CEO emails discussingaccounting matters for a longer period, such as 15 years. Thus, as oneexample, the tiered retention policy defines a further classificationcriteria (in addition to the mailbox owner (CEO)) including a searchterm (e.g., the term “accounting” with or without other related words).Where one or more search terms are used as a part of the classificationcriteria, the search term criteria is met if the tiered retention module250 finds the data item content and/or metadata. Thus, the tieredretention module 250 would search through the emails and theclassification criteria would be met for emails where the mailbox owneris the CEO and where the search term “accounting” is included in theemail content and/or metadata. A corresponding “15-year” bucket 540 iscreated in the storage devices 280, and the emails belonging to the15-year bucket 540 defined by this policy are migrated to the 15-yearbucket 540.

Emails that are addressed to a particular individual may have uniqueimportance. Thus, the CEO's emails to the CTO could be stored in yetanother, “9-year” bucket 550 with a 9-year retention period.Accordingly, for the 9-year bucket 550, the classification criteriawould dictate that e-mails having the CEO as the mailbox owner and theCTO as the email recipient are placed in the 9-year bucket 550. Asanother example, the policy could assign CEO emails relating to thestock market to yet another different bucket 560 with an 11-yearretention term. Finally, data not belonging to any particular bucket isstored in a default bucket 530, for example, with a 1-year retentionperiod.

Because all buckets may operate independently of one another, eventhough certain emails would be included in multiple buckets in the aboveexample, each bucket would maintain a pointer to or a copy of the data.That is, certain emails belonging to both the 7-year bucket 520 and15-year bucket 540 would not, by virtue of being included in the 15-yearbucket 540, be removed from the 7-year bucket 520 at the time they areadded to the 15-year bucket 540. The 7-year bucket 520 and the 15-yearbucket 540 would each have its own copy of the data in some form (i.e.,pointer or actual copy) so that the data can be pruned from the bucketwhen the retention period is up without regard to whether the data isincluded in other buckets or not.

As shown in FIG. 5, the data stored in the various buckets may becontent indexed to allow users to search the data. Data items sharing asame parent bucket could share a common content index. For instance, anyof the 15-year, 9-year, and 11-year buckets 540, 550, and 560, which arechild buckets of the 7-year bucket 520 in the bucket hierarchy, wouldshare a common content index. Alternatively, the data in the buckets canbe browsed without being content indexed.

Terminology

Conditional language, such as, among others, “can,” “could,” “might,” or“may,” unless specifically stated otherwise, or otherwise understoodwithin the context as used, is generally intended to convey that certainembodiments include, while other embodiments do not include, certainfeatures, elements and/or steps. Thus, such conditional language is notgenerally intended to imply that features, elements and/or steps are inany way required for one or more embodiments or that one or moreembodiments necessarily include logic for deciding, with or without userinput or prompting, whether these features, elements and/or steps areincluded or are to be performed in any particular embodiment.

Depending on the embodiment, certain acts, events, or functions of anyof the algorithms described herein can be performed in a differentsequence, can be added, merged, or left out all together (e.g., not alldescribed acts or events are necessary for the practice of thealgorithms). Moreover, in certain embodiments, acts or events can beperformed concurrently, e.g., through multi-threaded processing,interrupt processing, or multiple processors or processor cores or onother parallel architectures, rather than sequentially.

Systems and modules described herein may comprise software, firmware,hardware, or any combination(s) of software, firmware, or hardwaresuitable for the purposes described herein. Software and other modulesmay reside on servers, workstations, personal computers, computerizedtablets, PDAs, and other devices suitable for the purposes describedherein. Software and other modules may be accessible via local memory,via a network, via a browser, or via other means suitable for thepurposes described herein. Data structures described herein may comprisecomputer files, variables, programming arrays, programming structures,or any electronic information storage schemes or methods, or anycombinations thereof, suitable for the purposes described herein. Userinterface elements described herein may comprise elements from graphicaluser interfaces, command line interfaces, and other suitable interfaces.

Further, the processing of the various components of the illustratedsystems can be distributed across multiple machines, networks, and othercomputing resources. In addition, two or more components of a system canbe combined into fewer components. Various components of the illustratedsystems can be implemented in one or more virtual machines, rather thanin dedicated computer hardware systems. Likewise, the data repositoriesshown can represent physical and/or logical data storage, including, forexample, storage area networks or other distributed storage systems.Moreover, in some embodiments the connections between the componentsshown represent possible paths of data flow, rather than actualconnections between hardware. While some examples of possibleconnections are shown, any of the subset of the components shown cancommunicate with any other subset of components in variousimplementations.

Embodiments are also described above with reference to flow chartillustrations and/or block diagrams of methods, apparatus (systems) andcomputer program products. Each block of the flow chart illustrationsand/or block diagrams, and combinations of blocks in the flow chartillustrations and/or block diagrams, may be implemented by computerprogram instructions. Such instructions may be provided to a processorof a general purpose computer, special purpose computer, or otherprogrammable data processing apparatus to produce a machine, such thatthe instructions, which execute via the processor of the computer orother programmable data processing apparatus, create means forimplementing the acts specified in the flow chart and/or block diagramblock or blocks.

These computer program instructions may also be stored in acomputer-readable memory that can direct a computer or otherprogrammable data processing apparatus to operate in a particularmanner, such that the instructions stored in the computer-readablememory produce an article of manufacture including instruction meanswhich implement the acts specified in the flow chart and/or blockdiagram block or blocks. The computer program instructions may also beloaded onto a computer or other programmable data processing apparatusto cause a series of operations to be performed on the computer or otherprogrammable apparatus to produce a computer implemented process suchthat the instructions which execute on the computer or otherprogrammable apparatus provide steps for implementing the acts specifiedin the flow chart and/or block diagram block or blocks.

While certain embodiments have been described, these embodiments havebeen presented by way of example only, and are not intended to limit thescope of the disclosure. Indeed, the novel methods and systems describedherein may be embodied in a variety of other forms; furthermore, variousomissions, substitutions and changes in the form of the describedmethods and systems may be made without departing from the spirit of thedisclosure. The accompanying claims and their equivalents are intendedto cover such forms or modifications as would fall within the scope andspirit of the disclosure.

What is claimed is:
 1. A method for automatic, tiered data retention ina networked data storage system, comprising: copying primary datacomprising a plurality of data items generated by one or moreapplications executing on one or more client computers from primarystorage to secondary storage; receiving user input entered into agraphical user interface, the user input including first classificationcriteria and second classification criteria for at least first andsecond retention containers of a plurality of retention containerswithin the secondary storage, the first classification criteria and thesecond classification criteria each comprising at least one search term;accessing from computer storage a user-defined data retention policycomprising a set of classification criteria for assigning the pluralityof data items to the plurality of retention containers within thesecondary storage, each retention container associated with a particularretention period, the set of classification criteria comprising thefirst classification criteria and the second classification criteria;using computer hardware of one or more computers, automatically parsing,based on the user-defined data retention policy, through the pluralityof data items in the secondary storage to determine which data itemscontain an instance of the search term associated with the firstretention container; for one or more first data items that contain aninstance of the search term associated with the first retentioncontainer: assigning the first data items to the first retentioncontainer at least in part based on the determination that the firstdata items contain the search term, wherein the first data items arescheduled for deletion from the first retention container according tothe user-defined data retention policy only after the first data itemshave been retained for a duration that is at least as long as theretention period associated with the first retention container; usingcomputer hardware of one or more computers, automatically parsing, basedon the user-defined data retention policy, through the plurality of dataitems in the secondary storage to determine which data items contain aninstance of the search term associated with the second retentioncontainer; and for one or more second data items that contain aninstance of the search term associated with the second retentioncontainer: assigning the second data items to the second retentioncontainer at least in part based on the determination that the seconddata items contain the search term, wherein the second data items arescheduled for deletion from the second retention container according tothe user-defined data retention policy only after the second data itemshave been retained for a duration that is at least as long as theretention period associated with the second retention container.
 2. Themethod of claim 1, wherein said assigning comprises: if the dataretention policy does not comprise additional classification criteriafor the first retention container in addition to the search term,assigning the first data items to the first retention container based onsaid determination that the first data items contain an instance of thesearch term.
 3. The method of claim 1, wherein said assigning comprises:if the data retention policy does comprise additional classificationcriteria for the first retention container in addition to the searchterm, assigning the first data items to the first retention containeronly if the additional classification criteria is met in addition to thefirst data items containing an instance of the search term.
 4. Themethod of claim 1, wherein the plurality of retention containers areorganized in a hierarchy in which child retention containers include asubset of data items included in their respective parent retentioncontainers, and wherein the child retention containers have longerassociated retention periods than their respective parent retentioncontainers.
 5. The method of claim 1, wherein the first classificationcriteria for the first retention container of the plurality of retentioncontainers dictates that data items belong to the first retentioncontainer at least in part based on metadata associated with the dataitems meeting the first classification criteria.
 6. The method of claim1, wherein at least some of the data items comprise a plurality ofemails and said parsing to determine which data items contain aninstance of the search term associated with the first retentioncontainer further comprises parsing through at least message bodies ofindividual emails to determine which emails contain an instance of thesearch term of the first classification criteria.
 7. The method of claim1, wherein at least some of the data items comprise a plurality ofemails and the first classification criteria for the first retentioncontainer of the plurality of retention containers dictates that dataitems belong to the first retention container at least in part based onwhether the e-mails are associated with one or more of a particularmailbox owner, a particular sender, and a particular recipient.
 8. Themethod of claim 1, wherein the search term is entered by a user via thegraphical user interface.
 9. The method of claim 1, wherein the searchterm comprises at least one alphanumeric string of characters.
 10. Adata storage system configured for automatic, tiered data retention: acomputing system comprising one or more computing devices that includecomputer hardware, the computing system configured to: initiate copyingof primary data comprising a plurality of data items generated by one ormore applications executing on one or more client computers from primarystorage to secondary storage; receive user input entered into agraphical user interface, the user input including first classificationcriteria and second classification criteria for at least first andsecond retention containers of a plurality of retention containerswithin the secondary storage, the first classification criteria and thesecond classification criteria each comprising at least one search term;access from computer storage a user-defined data retention policycomprising a set of classification criteria for assigning the pluralityof data items to the plurality of retention containers within thesecondary storage, each retention container associated with a particularretention period, the set of classification criteria criteria comprisingthe first classification criteria and the second classificationcriteria; automatically parse, based on the user-defined data retentionpolicy, through the plurality of data items in the secondary storage todetermine which data items contain an instance of the search termassociated with the first retention container; for one or more firstdata items that contain an instance of the search term associated withthe first retention container: assign the one or more first data itemsto the first retention container at least in part based on thedetermination that the one or more first data items contain the searchterm, wherein the first data items are scheduled for deletion from thefirst retention container according to the user-defined data retentionpolicy only after the first data items have been retained for a durationthat is at least as long as the retention period associated with thefirst retention container; automatically parse, based on theuser-defined data retention policy, through the plurality of data itemsin the secondary storage to determine which data items contain aninstance of the search term associated with the second retentioncontainer; and for one or more second data items that contain aninstance of the search term associated with the second retentioncontainer: assign the second data items to the second retentioncontainer at least in part based on the determination that the seconddata items contain the search term, wherein the second data items arescheduled for deletion from the second retention container according tothe user-defined data retention policy only after the second data itemshave been retained for a duration that is at least as long as theretention period associated with the second retention container.
 11. Thedata storage system of claim 10, wherein the computing system is furtherconfigured to assign the first data items to the first retentioncontainer at least in part by: if the data retention policy does notcomprise additional classification criteria for the first retentioncontainer in addition to the search term, assigning the first data itemsto the first retention container based on the determination that thefirst data items contain the search term.
 12. The data storage system ofclaim 10, wherein the computing system is further configured to assignthe first data items to the first retention container at least in partby: if the data retention policy does comprise additional classificationcriteria for the first retention container in addition to the searchterm, assigning the first data items to the first retention containeronly if the additional classification criteria is met.
 13. The datastorage system of claim 10, wherein the plurality of retentioncontainers are organized in a hierarchy in which child retentioncontainers include a subset of data items included in their respectiveparent retention containers, wherein the child retention containers havelonger associated retention periods than their respective parentretention containers.
 14. The data storage system of claim 10, whereinthe first classification criteria for the first retention container ofthe plurality of retention containers dictates that data items belong tothe first retention container at least in part based on metadataassociated with the data items meeting the first classificationcriteria.
 15. The data storage system of claim 10, wherein at least someof the data items comprise a plurality of emails and the parsing todetermine which data items contain an instance of the search termassociated with the first retention container further comprises parsingthrough at least message bodies of individual emails to determine whichemails contain an instance of the search term of the firstclassification criteria.
 16. The data storage system of claim 10,wherein at least some of the data items comprise a plurality of emailsand the first classification criteria for the first retention containerof the plurality of retention containers dictates that data items belongto the first retention container at least in part based on whether thee-mails are associated with one or more of a particular mailbox owner, aparticular sender, and a particular recipient.
 17. The data storagesystem of claim 10, further comprising an interface through which a userenters the search term.
 18. The data storage system of claim 10, whereinthe search term comprises at least one alphanumeric string ofcharacters.